Steps to reproduce:

-Windows 10
-Installed 100.0.1/100.0.2 over 100.0.
-Uninstalled 100.0 and reinstalled 100.0.1/100.0.2 msi.

Actual results:

(Closed network environment) Once new version is installed (100.0.1/100.0.2) the browser becomes completely unresponsive (not frozen). Will not attempt to load any webpages that you enter in the URL bar. All buttons seem to be active but do not respond to any clicks. Cannot access settings or anything from the menu drop down.

Expected results:

Should've loaded our internal homepage.

Does the problem still happen if you start Firefox in Safe Mode? (Safe Mode disables add-ons, extensions and themes, hardware acceleration and some JavaScript stuff in order to exclude some possible reasons for problems.) See https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
And does this also happen with a new and empty profile? See https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems#w_6-create-a-new-firefox-profile

Everything seems to be operational in Safe Mode.

Do you use Windows Defender Exploit Guard? Outdated exploit protection settings break Firefox.

We do not use Defender Exploit Guard. We use McAfee ENS. I disabled McAfee and reinstalled. Still results. Mozilla install log does not show any errors. MacAfee logs do not show any features being blocked.

Just to be sure when you are not in safe mode would you:

• Navigate to about:config and accept the warning if you get it.
• Change security.sandbox.content.win32k-disable to false and restart Firefox.

I imagine this will also fix the issue.

Do you have anything in about:crashes that might be related that you could report and post here?

Browser does not respond when attempting to navigate to about:config / about:crashes.

(In reply to rick.botts25 from comment #6)

Browser does not respond when attempting to navigate to about:config / about:crashes.

Even when you have security.sandbox.content.win32k-disable set to false?
(Can you set it in safe mode?)

We figured it out. It was the DEP setting in Exploit protection. Once we turned that off the pages started resolving.

(In reply to rick.botts25 from comment #8)

We figured it out. It was the DEP setting in Exploit protection. Once we turned that off the pages started resolving.

Glad you found a solution, but I would be surprised if Data Execution Prevention would cause any problems.
Did you only turn that override off or did you remove all the program specific settings?

A needinfo is requested from the reporter, however, the reporter is inactive on Bugzilla. Closing the bug as incomplete.

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