firefox-49.0a2.en-US.win32 fails with "Can't load XPCOM" on Windows 10 Insider Preview build 14372.
Firefox Developer Edition 49.0.a2 fails to load on Windows 10 Pro Insider Preview build 14372 with the dreaded "Can't load XPCOM" error. I have tried reinstalling, uninstalling/reinstalling without success. The standard version of Firefox installed using the "Firefox Setup Stub 47.0.exe" does work correctly on this Windows Preview build however, So I will use that for now until there is a fix.
Chosen solution
Turns out this is not a Windows 10/Firefox Developer Edition Issue. It's instead a problem with Cylance <https://www.cylance.com> determining that some of Firefox Developer Edition's .DLL files are evil (or could be used for evil purposes)
Specifically it Quarantined the files: c:\program files (x86)\firefos\developer\edition\mozavutil.dll C:\Program Files (x86)\Firefox Developer Edition\lbplibs.dll
Cylance does not use signatures for finding malware, but instead uses heuristics to figure out what the code does (or is capable of) and unmercifully prevents all access to suspect files. To my knowledge Cylance (the company) does not provide a white-list of files or programs either. Local administrators can locally white-list files on a per-computer or per-site basis. As an equal opportunity hater, Cylance is also quarantining several of the SysInternals Suite of programs, as well as my Cygwin shell and compilers, too. That's why I'm on the Insider preview, for the new Ubuntu bash shell.
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hi ckloiber, are you using any sandboxing software on that system or is this happening on a pc with particularly old hardware?
No, this is on the Bare Metal. The hardware is an HP Compaq Pro 6300 (Intel I5-3470)
Chosen Solution
Turns out this is not a Windows 10/Firefox Developer Edition Issue. It's instead a problem with Cylance <https://www.cylance.com> determining that some of Firefox Developer Edition's .DLL files are evil (or could be used for evil purposes)
Specifically it Quarantined the files: c:\program files (x86)\firefos\developer\edition\mozavutil.dll C:\Program Files (x86)\Firefox Developer Edition\lbplibs.dll
Cylance does not use signatures for finding malware, but instead uses heuristics to figure out what the code does (or is capable of) and unmercifully prevents all access to suspect files. To my knowledge Cylance (the company) does not provide a white-list of files or programs either. Local administrators can locally white-list files on a per-computer or per-site basis. As an equal opportunity hater, Cylance is also quarantining several of the SysInternals Suite of programs, as well as my Cygwin shell and compilers, too. That's why I'm on the Insider preview, for the new Ubuntu bash shell.
thanks for the update!