hi, you can set the flash plugin to "ask to activate" in the firefox menu ≡ > addons > plugins section, then it shouldn't run by default on any website unless you chose so.

I don't have that option for Adobe Flash. Shockwave flash is set to ask to activate, but Adobe Flash doesn't show up in the list.

shockwave flash is the technical name for the adobe flash plugin, so you're all set already then...

No, I'm not all set. Shockwave Flash is set to Ask to Activate. Two instances of the Flash player plugin run whenever I start FireFox. I don't want it to run until I activate it.

How do I stop it from running until I approve its activation?

could you go to the firefox menu ≡ > help ? > troubleshooting information, copy the contents of that page and paste them here into a reply on the forum? this might give us a clue what is going on...

Troubleshooting Information Application Basics Name Firefox Version 44.0.2 Build ID 20160210153822 Update History Update Channel release User Agent Mozilla/5.0 (Windows NT 6.3; WOW64; rv:44.0) Gecko/20100101 Firefox/44.0 Profile Folder Enabled Plugins about:plugins Build Configuration about:buildconfig Memory Use about:memory Registered Service Workers about:serviceworkers Multiprocess Windows 0/1 (default: false) Safe Mode false Crash Reports for the Last 3 Days Report ID Submitted

All Crash Reports Extensions Name Version Enabled ID Adblock Plus 2.7.2 true {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d} Ghostery 6.0.2 true firefox@ghostery.com Graphics Adapter Description Intel(R) HD Graphics 4600 Adapter Drivers igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32 Adapter RAM Unknown Asynchronous Pan/Zoom none Device ID 0x0416 Direct2D Enabled true DirectWrite Enabled true (6.3.9600.18123) Driver Date 10-1-2013 Driver Version 10.18.10.3316 GPU #2 Active false GPU Accelerated Windows 1/1 Direct3D 11 (OMTC) Subsys ID 1993103c Supports Hardware H264 Decoding Yes Vendor ID 0x8086 WebGL Renderer Google Inc. -- ANGLE (Intel(R) HD Graphics 4600 Direct3D11 vs_5_0 ps_5_0) windowLayerManagerRemote true AzureCanvasBackend direct2d 1.1 AzureContentBackend direct2d 1.1 AzureFallbackCanvasBackend cairo AzureSkiaAccelerated 0 Important Modified Preferences Name Value accessibility.blockautorefresh true accessibility.typeaheadfind.flashBar 0 browser.cache.disk.capacity 358400 browser.cache.disk.filesystem_reported 1 browser.cache.disk.smart_size.first_run false browser.cache.disk.smart_size.use_old_max false browser.cache.frecency_experiment 2 browser.download.importedFromSqlite true browser.download.manager.alertOnEXEOpen false browser.download.useDownloadDir false browser.link.open_newwindow 2 browser.places.smartBookmarksVersion 7 browser.privatebrowsing.autostart true browser.sessionstore.upgradeBackup.latestBuildID 20150122214805 browser.startup.homepage http://duckduckgo.com browser.startup.homepage_override.buildID 20160210153822 browser.startup.homepage_override.mstone 44.0.2 browser.tabs.drawInTitlebar false browser.urlbar.autocomplete.enabled false browser.urlbar.suggest.bookmark false browser.urlbar.suggest.history false browser.urlbar.suggest.openpage false dom.apps.reset-permissions true dom.max_script_run_time 0 dom.mozApps.used true extensions.lastAppVersion 44.0.2 font.internaluseonly.changed true gfx.crash-guard.d3d11layers.appVersion 44.0.2 gfx.crash-guard.d3d11layers.deviceID 0x0416 gfx.crash-guard.d3d11layers.driverVersion 10.18.10.3316 gfx.crash-guard.d3d11layers.feature-d2d true gfx.crash-guard.d3d11layers.feature-d3d11 true gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11 false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11 true gfx.crash-guard.status.d3d11layers 2 gfx.crash-guard.status.d3d9video 2 gfx.crash-guard.status.glcontext 2 gfx.direct3d.last_used_feature_level_idx 0 gfx.driver-init.appVersion 42.0 gfx.driver-init.deviceID 0x0416 gfx.driver-init.driverVersion 10.18.10.3316 gfx.driver-init.feature-d2d true gfx.driver-init.feature-d3d11 true gfx.driver-init.status 2 media.gmp-eme-adobe.abi x86-msvc media.gmp-eme-adobe.enabled false media.gmp-eme-adobe.lastUpdate 1447247819 media.gmp-eme-adobe.version 15 media.gmp-gmpopenh264.abi x86-msvc-x64 media.gmp-gmpopenh264.lastUpdate 1455351502 media.gmp-gmpopenh264.version 1.5.3 media.gmp-manager.buildID 20160210153822 media.gmp-manager.lastCheck 1457532139 media.hardware-video-decoding.failed false network.auth.allow-subresource-auth 2 network.cookie.cookieBehavior 1 network.cookie.prefsMigrated true network.predictor.cleaned-up true places.database.lastMaintenance 1456853533 places.history.expiration.transient_current_max_pages 104858 plugin.disable_full_page_plugin_for_types application/pdf plugin.importedState true plugin.state.flash 1 plugin.state.npdeployjava 0 plugin.state.npitunes 0 plugin.state.npmeetingjoinpluginoc 0 plugin.state.nppdfxcviewnpplugin 2 plugin.state.npspwrap 0 print.printer_Microsoft_XPS_Document_Writer.print_bgcolor false print.printer_Microsoft_XPS_Document_Writer.print_bgimages false print.printer_Microsoft_XPS_Document_Writer.print_colorspace print.printer_Microsoft_XPS_Document_Writer.print_command print.printer_Microsoft_XPS_Document_Writer.print_downloadfonts false print.printer_Microsoft_XPS_Document_Writer.print_duplex 1515870810 print.printer_Microsoft_XPS_Document_Writer.print_edge_bottom 0 print.printer_Microsoft_XPS_Document_Writer.print_edge_left 0 print.printer_Microsoft_XPS_Document_Writer.print_edge_right 0 print.printer_Microsoft_XPS_Document_Writer.print_edge_top 0 print.printer_Microsoft_XPS_Document_Writer.print_evenpages true print.printer_Microsoft_XPS_Document_Writer.print_footercenter print.printer_Microsoft_XPS_Document_Writer.print_footerleft &PT print.printer_Microsoft_XPS_Document_Writer.print_footerright &D print.printer_Microsoft_XPS_Document_Writer.print_headercenter print.printer_Microsoft_XPS_Document_Writer.print_headerleft &T print.printer_Microsoft_XPS_Document_Writer.print_headerright &U print.printer_Microsoft_XPS_Document_Writer.print_in_color true print.printer_Microsoft_XPS_Document_Writer.print_margin_bottom 0.5 print.printer_Microsoft_XPS_Document_Writer.print_margin_left 0.5 print.printer_Microsoft_XPS_Document_Writer.print_margin_right 0.5 print.printer_Microsoft_XPS_Document_Writer.print_margin_top 0.5 print.printer_Microsoft_XPS_Document_Writer.print_oddpages true print.printer_Microsoft_XPS_Document_Writer.print_orientation 0 print.printer_Microsoft_XPS_Document_Writer.print_page_delay 50 print.printer_Microsoft_XPS_Document_Writer.print_paper_data 1 print.printer_Microsoft_XPS_Document_Writer.print_paper_height 11.00 print.printer_Microsoft_XPS_Document_Writer.print_paper_name print.printer_Microsoft_XPS_Document_Writer.print_paper_size_type 0 print.printer_Microsoft_XPS_Document_Writer.print_paper_size_unit 0 print.printer_Microsoft_XPS_Document_Writer.print_paper_width 8.50 print.printer_Microsoft_XPS_Document_Writer.print_plex_name print.printer_Microsoft_XPS_Document_Writer.print_resolution 1515870810 print.printer_Microsoft_XPS_Document_Writer.print_resolution_name print.printer_Microsoft_XPS_Document_Writer.print_reversed false print.printer_Microsoft_XPS_Document_Writer.print_scaling 1.00 print.printer_Microsoft_XPS_Document_Writer.print_shrink_to_fit true print.printer_Microsoft_XPS_Document_Writer.print_to_file true print.printer_Microsoft_XPS_Document_Writer.print_unwriteable_margin_bottom 0 print.printer_Microsoft_XPS_Document_Writer.print_unwriteable_margin_left 0 print.printer_Microsoft_XPS_Document_Writer.print_unwriteable_margin_right 0 print.printer_Microsoft_XPS_Document_Writer.print_unwriteable_margin_top 0 privacy.donottrackheader.enabled true privacy.sanitize.didShutdownSanitize true privacy.sanitize.migrateClearSavedPwdsOnExit true privacy.sanitize.migrateFx3Prefs true privacy.sanitize.sanitizeOnShutdown true privacy.trackingprotection.enabled true security.disable_button.openCertManager false security.disable_button.openDeviceManager false security.OCSP.enabled 0 storage.vacuum.last.index 1 storage.vacuum.last.places.sqlite 1455809376 ui.o

thanks - could you test if it does make a difference if you go to the firefox menu ≡ > options > privacy panel and disable "Clear history when Firefox closes". afaik this is the only option in firefox that might trigger the execution of the flash plugin and this is done in order to clear flash cookies. maybe there has been an issue sanitising on shutdown so this action is repeated after the next start of the browser...

That setting is grayed-out. I can't change it.

then please enter about:config into the firefox address bar (confirm the info message in case it shows up) and search for the preferences named privacy.sanitize.sanitizeOnShutdown & privacy.sanitize.didShutdownSanitize - right-click and reset those entries to their default value.

Thanks. That stopped FlashPlayer from loading at startup.

So, since I'm always running in Private Mode, the next questions I have to ask are:

• if I activate Flash at any time, will it stay running until I shutdown FireFox?
• Will Flash clear out its cache when I shutdown FireFox?

As you can probably tell, I'm not a fan of Adobe Flash. There are way too many vulnerabilities written for it and I like to keep my PC as protected as possible. I want to make sure it shuts down when I'm not using it, and that it empties out its cache when it does shut down.

FFUser11 said

• if I activate Flash at any time, will it stay running until I shutdown FireFox?

if you activate flash for a particular site, i think flash content will be able to run as long you have that site open & it will also be activated automatically if you visit the same domain again within 60 minutes (time-span is controlled in the plugin.sessionPermissionNow.intervalInMinutes).

• Will Flash clear out its cache when I shutdown FireFox?

actually i'm not sure how flash behaves there, but you could check yourself if there are cookies created during a session/cleared after a session, as all flash cookies are stored on your harddrive under %appdata%\Macromedia\Flash Player\#SharedObjects

personally, i have set up a task that is running on regular intervals on my system and executes a script that just clears that folder...

Thanks for all your help. I'll be sure to get that script working on my PC.