I've had Firefox running on this PC for a couple of years and started running into problems with it. I've tried refreshing, reinstalling, restoring the machine back to prior system restore points, nothing seems to work. It all seems to revolve around the ntdll.dll. I've included some event viewer info and the content of Report.wer. It seems Firefox has been banned from this machine. Let me know if there is anything else I should provide. Thanks. Faulting application name: firefox.exe, version: 89.0.0.7817, time stamp: 0x60afecf6 Faulting module name: ntdll.dll, version: 10.0.19041.964, time stamp: 0xbd2c3c23 Exception code: 0xc0000005 Fault offset: 0x000000000001ad67 Faulting process id: 0x582c Faulting application start time: 0x01d757b00294012c Faulting application path: C:\Program Files\Mozilla Firefox\firefox.exe Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll Report Id: 1afb044a-bf7e-4020-b084-08f882aaf94c Faulting package full name: Faulting package-relative application ID: Version=1 EventType=APPCRASH EventTime=132671127503826359 ReportType=2 Consent=1 UploadTime=132671127507247212 ReportStatus=268435456 ReportIdentifier=e315cba1-ca8c-40bf-b0ac-9a142bb7cee1 IntegratorReportIdentifier=113620e8-2ede-466f-98e3-b91d252845e1 Wow64Host=34404 NsAppName=firefox.exe OriginalFilename=firefox.exe AppSessionGuid=00003b48-0001-0037-5262-9c02b057d701 TargetAppId=W:000674066830d6caf8b2219dfd54a0b76a3800000000!00008dd035bd088253590fa20cfecc38a76424eb2feb!firefox.exe TargetAppVer=2021//05//27:19:03:18!93ae6!firefox.exe BootId=4294967295 TargetAsId=42676 IsFatal=1 EtwNonCollectReason=1 Response.BucketId=f59497a5b16ecbe06f93fccb8359c389 Response.BucketTable=4 Response.LegacyBucketId=2275440187764491145 Response.type=4 Sig[0].Name=Application Name Sig[0].Value=firefox.exe Sig[1].Name=Application Version Sig[1].Value=89.0.0.7817 Sig[2].Name=Application Timestamp Sig[2].Value=60afecf6 Sig[3].Name=Fault Module Name Sig[3].Value=ntdll.dll Sig[4].Name=Fault Module Version Sig[4].Value=10.0.19041.964 Sig[5].Name=Fault Module Timestamp Sig[5].Value=bd2c3c23 Sig[6].Name=Exception Code Sig[6].Value=c0000005 Sig[7].Name=Exception Offset Sig[7].Value=000000000001ad67 DynamicSig[1].Name=OS Version DynamicSig[1].Value=10.0.19042.2.0.0.256.48 DynamicSig[2].Name=Locale ID DynamicSig[2].Value=1033 DynamicSig[22].Name=Additional Information 1 DynamicSig[22].Value=0000 DynamicSig[23].Name=Additional Information 2 DynamicSig[23].Value=00000000000000000000000000000000 DynamicSig[24].Name=Additional Information 3 DynamicSig[24].Value=0000 DynamicSig[25].Name=Additional Information 4 DynamicSig[25].Value=00000000000000000000000000000000 UI[2]=C:\Program Files\Mozilla Firefox\firefox.exe LoadedModule[0]=C:\Program Files\Mozilla Firefox\firefox.exe LoadedModule[1]=C:\WINDOWS\SYSTEM32\ntdll.dll LoadedModule[2]=C:\WINDOWS\System32\KERNEL32.DLL LoadedModule[3]=C:\WINDOWS\System32\KERNELBASE.dll LoadedModule[4]=C:\WINDOWS\SYSTEM32\apphelp.dll LoadedModule[5]=C:\Program Files\Norton Security\{EA97DD3A-7978-4E82-83EE-5B9F07E0C020}\NortonData\22.21.1.151\Definitions\IPSDefs\20210601.061\IPSEng64.dll LoadedModule[6]=C:\WINDOWS\System32\ADVAPI32.dll LoadedModule[7]=C:\WINDOWS\System32\msvcrt.dll LoadedModule[8]=C:\WINDOWS\System32\sechost.dll LoadedModule[9]=C:\WINDOWS\System32\RPCRT4.dll LoadedModule[10]=C:\WINDOWS\System32\PSAPI.DLL LoadedModule[11]=C:\WINDOWS\System32\ucrtbase.dll LoadedModule[12]=C:\Program Files\Mozilla Firefox\mozglue.dll LoadedModule[13]=C:\WINDOWS\System32\CRYPT32.dll LoadedModule[14]=C:\WINDOWS\System32\WINTRUST.dll LoadedModule[15]=C:\WINDOWS\SYSTEM32\MSVCP140.dll LoadedModule[16]=C:\WINDOWS\SYSTEM32\VCRUNTIME140.dll LoadedModule[17]=C:\WINDOWS\SYSTEM32\VERSION.dll LoadedModule[18]=C:\WINDOWS\SYSTEM32\dbghelp.dll LoadedModule[19]=C:\WINDOWS\SYSTEM32\VCRUNTIME140_1.dll LoadedModule[20]=C:\WINDOWS\SYSTEM32\CRYPTBASE.DLL LoadedModule[21]=C:\WINDOWS\SYSTEM32\MSASN1.dll State[0].Key=Transport.DoneStage1 State[0].Value=1 OsInfo[0].Key=vermaj OsInfo[0].Value=10 OsInfo[1].Key=vermin OsInfo[1].Value=0 OsInfo[2].Key=verbld OsInfo[2].Value=19042 OsInfo[3].Key=ubr OsInfo[3].Value=985 OsInfo[4].Key=versp OsInfo[4].Value=0 OsInfo[5].Key=arch OsInfo[5].Value=9 OsInfo[6].Key=lcid OsInfo[6].Value=1033 OsInfo[7].Key=geoid OsInfo[7].Value=244 OsInfo[8].Key=sku OsInfo[8].Value=48 OsInfo[9].Key=domain OsInfo[9].Value=0 OsInfo[10].Key=prodsuite OsInfo[10].Value=256 OsInfo[11].Key=ntprodtype OsInfo[11].Value=1 OsInfo[12].Key=platid OsInfo[12].Value=10 OsInfo[13].Key=sr OsInfo[13].Value=0 OsInfo[14].Key=tmsi OsInfo[14].Value=221115844 OsInfo[15].Key=osinsty OsInfo[15].Value=3 OsInfo[16].Key=iever OsInfo[16].Value=11.789.19041.0-11.0.1000 OsInfo[17].Key=portos OsInfo[17].Value=0 OsInfo[18].Key=ram OsInfo[18].Value=32631 OsInfo[19].Key=svolsz OsInfo[19].Value=952 OsInfo[20].Key=wimbt OsInfo[20].Value=0 OsInfo[21].Key=blddt OsInfo[21].Value=191206 OsInfo[22].Key=bldtm OsInfo[22].Value=1406 OsInfo[23].Key=bldbrch OsInfo[23].Value=vb_release OsInfo[24].Key=bldchk OsInfo[24].Value=0 OsInfo[25].Key=wpvermaj OsInfo[25].Value=0 OsInfo[26].Key=wpvermin OsInfo[26].Value=0 OsInfo[27].Key=wpbuildmaj OsInfo[27].Value=0 OsInfo[28].Key=wpbuildmin OsInfo[28].Value=0 OsInfo[29].Key=osver OsInfo[29].Value=10.0.19041.985.amd64fre.vb_release.191206-1406 OsInfo[30].Key=buildflightid OsInfo[30].Value=C0DD2958-3F6C-41DD-85BE-41F4BE4DFAC2.1 OsInfo[31].Key=edition OsInfo[31].Value=Professional OsInfo[32].Key=ring OsInfo[32].Value=Retail OsInfo[33].Key=expid OsInfo[34].Key=fconid OsInfo[35].Key=containerid OsInfo[36].Key=containertype OsInfo[37].Key=edu OsInfo[37].Value=0 FriendlyEventName=Stopped working ConsentKey=APPCRASH AppName=Firefox AppPath=C:\Program Files\Mozilla Firefox\firefox.exe NsPartner=windows NsGroup=windows8 ApplicationIdentity=67E97FB536942A9129100B62F2DE4AEB MetadataHash=1807917528