Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Natao arisiva ity resaka mitohy ity. Mametraha fanontaniana azafady raha mila fanampiana.

After hanging while trying to save a bookmark, Firefox now hangs when I select Show All Bookmarks

  • 6 valiny
  • 2 manana an'ity olana ity
  • 1 view
  • Valiny farany nomen'i FredMcD

more options

I was saving a bookmark using "Add Bookmark" from the menu bar, but the window where you select the folder froze. Firefox became unresponsive. I force quit. When Firefox restarted, I tried Show All Bookmarks to see if that bookmark had saved or not. But that made Firefox hang again, and so did repeated attempts.

Here is the crash dump: Date/Time: 2016-08-12 17:48:13 -0700 OS Version: Mac OS X 10.11.6 (Build 15G31) Architecture: x86_64h Report Version: 22

Command: Firefox Path: /Applications/Firefox.app/Contents/MacOS/firefox Version: 48.0 (4816.7.26) Parent: launchd [1] PID: 2748

Event: hang Duration: 1.10s (process was unresponsive for 18 seconds before sampling) Steps: 11 (100ms sampling interval)

Hardware model: iMac17,1 Active cpus: 8

Fan speed: 1201 rpm


Timeline format: stacks are sorted chronologically Use -i and -heavy to re-report with count sorting


Heaviest stack for the main thread of the target process:

 11  ??? [0x7fff7391bce0]
 11  ??? [0x7c8]
 11  ??? (<31788F2D-B33C-3041-A084-96766B946A2C> + 30901084) [0x10302e35c]
 11  -[NSPasteboard stringForType:] + 31 (AppKit + 6931299) [0x7fff84ce7363]
 11  -[NSPasteboard _dataForType:securityScoped:] + 91 (AppKit + 6930912) [0x7fff84ce71e0]
 11  -[NSPasteboard _dataForType:index:usesPboardTypes:combinesItems:securityScoped:] + 277 (AppKit + 6925859) [0x7fff84ce5e23]
 11  -[NSPasteboard _dataWithoutConversionForTypeIdentifier:securityScoped:] + 453 (AppKit + 6925225) [0x7fff84ce5ba9]
 11  CFPasteboardCopyData + 27 (CoreFoundation + 686347) [0x7fff89fc790b]
 11  __CFPasteboardCopyData + 2688 (CoreFoundation + 689056) [0x7fff89fc83a0]
 11  __semwait_signal + 10 (libsystem_kernel.dylib + 94474) [0x7fff8a53d10a]
*11  semaphore_wait_continue + 0 (kernel + 1029568) [0xffffff80002fb5c0]


Process: firefox (Firefox) [2748] Path: /Applications/Firefox.app/Contents/MacOS/firefox Architecture: x86_64 Parent: launchd [1] UID: 503 Task size: 238901 pages (+2) CPU Time: 0.021s Note: Unresponsive for 18 seconds before sampling Note: 2 idle work queue threads omitted

 Thread 0x236d45         DispatchQueue 1         11 samples (1-11)       priority 46-47 (base 46-47)                     cpu time 0.018s
 <process frontmost, thread QoS user interactive (requested user interactive), process unclamped, process received importance donation from WindowServer [167], IO policy important, priority 47 (47)>
 11  ??? [0x7fff7391bce0] 1-11
   11  ??? [0x7c8] 1-11
     11  ??? (<31788F2D-B33C-3041-A084-96766B946A2C> + 30901084) [0x10302e35c] 1-11
       11  -[NSPasteboard stringForType:] + 31 (AppKit + 6931299) [0x7fff84ce7363] 1-11
         11  -[NSPasteboard _dataForType:securityScoped:] + 91 (AppKit + 6930912) [0x7fff84ce71e0] 1-11
           11  -[NSPasteboard _dataForType:index:usesPboardTypes:combinesItems:securityScoped:] + 277 (AppKit + 6925859) [0x7fff84ce5e23] 1-11
             11  -[NSPasteboard _dataWithoutConversionForTypeIdentifier:securityScoped:] + 453 (AppKit + 6925225) [0x7fff84ce5ba9] 1-11
               11  CFPasteboardCopyData + 27 (CoreFoundation + 686347) [0x7fff89fc790b] 1-11
                 11  __CFPasteboardCopyData + 2688 (CoreFoundation + 689056) [0x7fff89fc83a0] 1-11
                   11  __semwait_signal + 10 (libsystem_kernel.dylib + 94474) [0x7fff8a53d10a] 1-11
                    *7   semaphore_wait_continue + 0 (kernel + 1029568) [0xffffff80002fb5c0] 1-7
 <process non-frontmost, priority 46 (46)>
                    *4   semaphore_wait_continue + 0 (kernel + 1029568) [0xffffff80002fb5c0] 8-11
 Thread 0x236da4         DispatchQueue 2         11 samples (1-11)       priority 46-47 (base 46-47)
 <process frontmost, thread QoS user interactive (requested user interactive), process unclamped, process received importance donation from WindowServer [167], IO policy important, priority 47 (47)>
 11  _dispatch_mgr_thread + 52 (libdispatch.dylib + 32205) [0x7fff91ab3dcd] 1-11
   11  kevent_qos + 10 (libsystem_kernel.dylib + 98042) [0x7fff8a53defa] 1-11
    *7   ??? (kernel + 5828144) [0xffffff800078ee30] 1-7
 <process non-frontmost, priority 46 (46)>
    *4   ??? (kernel + 5828144) [0xffffff800078ee30] 8-11
 Thread 0x236dac         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  thread_start + 13 (libsystem_pthread.dylib + 4945) [0x7fff920fd351] 1-11
   11  _pthread_start + 168 (libsystem_pthread.dylib + 14618) [0x7fff920ff91a] 1-11
     11  ??? (<31788F2D-B33C-3041-A084-96766B946A2C> + 40714335) [0x10398a05f] 1-11
       11  mach_msg_trap + 10 (libsystem_kernel.dylib + 69490) [0x7fff8a536f72] 1-11
        *7   ipc_mqueue_receive_continue + 0 (kernel + 812688) [0xffffff80002c6690] 1-7
 <process non-frontmost>
        *4   ipc_mqueue_receive_continue + 0 (kernel + 812688) [0xffffff80002c6690] 8-11
 Thread 0x236dd5         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  kevent + 10 (libsystem_kernel.dylib + 97994) [0x7fff8a53deca] 1-11
  *7   ??? (kernel + 5828144) [0xffffff800078ee30] 1-7
 <process non-frontmost>
  *4   ??? (kernel + 5828144) [0xffffff800078ee30] 8-11
 Thread 0x236ddc         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  __select + 10 (libsystem_kernel.dylib + 94330) [0x7fff8a53d07a] 1-11
  *7   ??? (kernel + 5989200) [0xffffff80007b6350] 1-7
 <process non-frontmost>
  *4   ??? (kernel + 5989200) [0xffffff80007b6350] 8-11
 Thread 0x236e01         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175699) [0x1012132d3] 1-11
   11  __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11
    *7   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7
 <process non-frontmost>
    *4   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11
 Thread 0x236e05         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11
   11  __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11
    *7   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7
 <process non-frontmost>
    *4   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11
 Thread 0x236e07         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11
   11  __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11
    *7   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7
 <process non-frontmost>
    *4   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11
 Thread 0x236e08         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11
   11  __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11
    *7   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7
 <process non-frontmost>
    *4   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11
 Thread 0x236e09         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11
   11  __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11
    *7   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7
 <process non-frontmost>
    *4   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11
 Thread 0x236e0a         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
 11  ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11
   11  __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11
    *7   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7
 <process non-frontmost>
    *4   psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11
 Thread 0x236e0b         11 samples (1-11)       priority 31 (base 31)
 <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>
I was saving a bookmark using "Add Bookmark" from the menu bar, but the window where you select the folder froze. Firefox became unresponsive. I force quit. When Firefox restarted, I tried Show All Bookmarks to see if that bookmark had saved or not. But that made Firefox hang again, and so did repeated attempts. Here is the crash dump: Date/Time: 2016-08-12 17:48:13 -0700 OS Version: Mac OS X 10.11.6 (Build 15G31) Architecture: x86_64h Report Version: 22 Command: Firefox Path: /Applications/Firefox.app/Contents/MacOS/firefox Version: 48.0 (4816.7.26) Parent: launchd [1] PID: 2748 Event: hang Duration: 1.10s (process was unresponsive for 18 seconds before sampling) Steps: 11 (100ms sampling interval) Hardware model: iMac17,1 Active cpus: 8 Fan speed: 1201 rpm -------------------------------------------------- Timeline format: stacks are sorted chronologically Use -i and -heavy to re-report with count sorting -------------------------------------------------- Heaviest stack for the main thread of the target process: 11 ??? [0x7fff7391bce0] 11 ??? [0x7c8] 11 ??? (<31788F2D-B33C-3041-A084-96766B946A2C> + 30901084) [0x10302e35c] 11 -[NSPasteboard stringForType:] + 31 (AppKit + 6931299) [0x7fff84ce7363] 11 -[NSPasteboard _dataForType:securityScoped:] + 91 (AppKit + 6930912) [0x7fff84ce71e0] 11 -[NSPasteboard _dataForType:index:usesPboardTypes:combinesItems:securityScoped:] + 277 (AppKit + 6925859) [0x7fff84ce5e23] 11 -[NSPasteboard _dataWithoutConversionForTypeIdentifier:securityScoped:] + 453 (AppKit + 6925225) [0x7fff84ce5ba9] 11 CFPasteboardCopyData + 27 (CoreFoundation + 686347) [0x7fff89fc790b] 11 __CFPasteboardCopyData + 2688 (CoreFoundation + 689056) [0x7fff89fc83a0] 11 __semwait_signal + 10 (libsystem_kernel.dylib + 94474) [0x7fff8a53d10a] *11 semaphore_wait_continue + 0 (kernel + 1029568) [0xffffff80002fb5c0] Process: firefox (Firefox) [2748] Path: /Applications/Firefox.app/Contents/MacOS/firefox Architecture: x86_64 Parent: launchd [1] UID: 503 Task size: 238901 pages (+2) CPU Time: 0.021s Note: Unresponsive for 18 seconds before sampling Note: 2 idle work queue threads omitted Thread 0x236d45 DispatchQueue 1 11 samples (1-11) priority 46-47 (base 46-47) cpu time 0.018s <process frontmost, thread QoS user interactive (requested user interactive), process unclamped, process received importance donation from WindowServer [167], IO policy important, priority 47 (47)> 11 ??? [0x7fff7391bce0] 1-11 11 ??? [0x7c8] 1-11 11 ??? (<31788F2D-B33C-3041-A084-96766B946A2C> + 30901084) [0x10302e35c] 1-11 11 -[NSPasteboard stringForType:] + 31 (AppKit + 6931299) [0x7fff84ce7363] 1-11 11 -[NSPasteboard _dataForType:securityScoped:] + 91 (AppKit + 6930912) [0x7fff84ce71e0] 1-11 11 -[NSPasteboard _dataForType:index:usesPboardTypes:combinesItems:securityScoped:] + 277 (AppKit + 6925859) [0x7fff84ce5e23] 1-11 11 -[NSPasteboard _dataWithoutConversionForTypeIdentifier:securityScoped:] + 453 (AppKit + 6925225) [0x7fff84ce5ba9] 1-11 11 CFPasteboardCopyData + 27 (CoreFoundation + 686347) [0x7fff89fc790b] 1-11 11 __CFPasteboardCopyData + 2688 (CoreFoundation + 689056) [0x7fff89fc83a0] 1-11 11 __semwait_signal + 10 (libsystem_kernel.dylib + 94474) [0x7fff8a53d10a] 1-11 *7 semaphore_wait_continue + 0 (kernel + 1029568) [0xffffff80002fb5c0] 1-7 <process non-frontmost, priority 46 (46)> *4 semaphore_wait_continue + 0 (kernel + 1029568) [0xffffff80002fb5c0] 8-11 Thread 0x236da4 DispatchQueue 2 11 samples (1-11) priority 46-47 (base 46-47) <process frontmost, thread QoS user interactive (requested user interactive), process unclamped, process received importance donation from WindowServer [167], IO policy important, priority 47 (47)> 11 _dispatch_mgr_thread + 52 (libdispatch.dylib + 32205) [0x7fff91ab3dcd] 1-11 11 kevent_qos + 10 (libsystem_kernel.dylib + 98042) [0x7fff8a53defa] 1-11 *7 ??? (kernel + 5828144) [0xffffff800078ee30] 1-7 <process non-frontmost, priority 46 (46)> *4 ??? (kernel + 5828144) [0xffffff800078ee30] 8-11 Thread 0x236dac 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 thread_start + 13 (libsystem_pthread.dylib + 4945) [0x7fff920fd351] 1-11 11 _pthread_start + 168 (libsystem_pthread.dylib + 14618) [0x7fff920ff91a] 1-11 11 ??? (<31788F2D-B33C-3041-A084-96766B946A2C> + 40714335) [0x10398a05f] 1-11 11 mach_msg_trap + 10 (libsystem_kernel.dylib + 69490) [0x7fff8a536f72] 1-11 *7 ipc_mqueue_receive_continue + 0 (kernel + 812688) [0xffffff80002c6690] 1-7 <process non-frontmost> *4 ipc_mqueue_receive_continue + 0 (kernel + 812688) [0xffffff80002c6690] 8-11 Thread 0x236dd5 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 kevent + 10 (libsystem_kernel.dylib + 97994) [0x7fff8a53deca] 1-11 *7 ??? (kernel + 5828144) [0xffffff800078ee30] 1-7 <process non-frontmost> *4 ??? (kernel + 5828144) [0xffffff800078ee30] 8-11 Thread 0x236ddc 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 __select + 10 (libsystem_kernel.dylib + 94330) [0x7fff8a53d07a] 1-11 *7 ??? (kernel + 5989200) [0xffffff80007b6350] 1-7 <process non-frontmost> *4 ??? (kernel + 5989200) [0xffffff80007b6350] 8-11 Thread 0x236e01 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175699) [0x1012132d3] 1-11 11 __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11 *7 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7 <process non-frontmost> *4 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11 Thread 0x236e05 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11 11 __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11 *7 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7 <process non-frontmost> *4 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11 Thread 0x236e07 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11 11 __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11 *7 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7 <process non-frontmost> *4 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11 Thread 0x236e08 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11 11 __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11 *7 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7 <process non-frontmost> *4 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11 Thread 0x236e09 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11 11 __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11 *7 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7 <process non-frontmost> *4 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11 Thread 0x236e0a 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important> 11 ??? (<269048EC-6715-3ED9-853D-E3D8E3C271E7> + 2175725) [0x1012132ed] 1-11 11 __psynch_cvwait + 10 (libsystem_kernel.dylib + 93622) [0x7fff8a53cdb6] 1-11 *7 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 1-7 <process non-frontmost> *4 psynch_cvcontinue + 0 (pthread + 30218) [0xffffff7f80e8e60a] 8-11 Thread 0x236e0b 11 samples (1-11) priority 31 (base 31) <process frontmost, thread QoS legacy (requested legacy), process unclamped, process received importance donation from WindowServer [167], IO policy important>

All Replies (6)

more options

Installed Plug-ins

I don't know how to find this info in Firefox anymore. Flash, Web Developer, ??

This is done automatically by the website if you allow it.

Please add this program to your Firefox. SUMO Troubleshooter {web link} This will provide Firefox troubleshooting data to Mozilla websites. No personal information is listed.


Was it Firefox that reported the crash, or your system?

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP in front of the numbers/letters, click it to submit them.

The crash report is several pages of data. We need the report numbers to see the whole report.

Using your mouse, mark the most resent 7 - 10 crash reports, and copy them. Now go to the reply box below and paste them in.

aboutcrashesFx29
more options

Firefox repeatedly hung, and I force quit.

more options

BTW I think it's wack to have to install a separate program just to see a list of your plug-ins.

more options

SUMO Troubleshooter allows the website to look at your system.

If you want to see your own plugins, Type about:plugins<enter> in the address bar.


Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

more options

Thanks. After starting in Safe Mode, I was able to view bookmarks. So what does that mean? Is there a next step?

more options

It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac=<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is, detective.