Internet Explorer Mode broken in Edge Dev Version 80.0.361.9

[GreatToHearFromYou]

As of Edge Dev Version 80.0.361.9 Internet Explorer Mode is not working natively in Edge anymore and instead opens the link in a new Internet Explorer Window and showing a message in Edge stating "To open this page in Internet Explorer mode, reinstall Microsoft Edge with administrator privileges"

Internet Explorer Mode worked perfectly fine with Edge Dev Version 80.0.361.5

Needless to say (because it was working perfectly fine before), but it seems to be the standard question; Edge is installed in the Programs Files folder: C:\Program Files (x86)\Microsoft\Edge Dev\Application\msedge.exe

[#2]

@dmcaylor 

Are your computers on a Domain and do you get any GPO's pushed through your Domain? If so, it may be one of those Policies causing the issue. That's what I want to test in our environment, but time is currently unfortunately not on my side.

Sorry, I missed your first part, I will test that, creating a new user on the same computer.

[#3]

@dmcaylor 

For us, the same issue appears also with a new user profile. While I was working with the new profile, I also tested if it had anything to do with the xml file that determines the app defaults, I've set the default apps to Windows recommended (automatically making Edge the default browser), rebooted without our "default xml file", but the problem is still there.

Since all was working fine until we got Version 80.0.361.9, which broke all other versions as well, I am also not sure if it is a Policy Setting. However, it is certainly a combination of the update and whatever settings we have on our computers that suddenly broke it, because most people who posted on this thread are fine, or were effected but then fine after an new version update.

[#4]

@GreatToHearFromYou @dmcaylor If you still have this issue, are you able to share an RSOP report of policies you have on the machine? We can help troubleshoot if there are any conflicting policies that might be causing the issue.

[#5]

@Shilpa_Subramanian 

Yes, this is still an issue. I've sent you the RSOP Report in a private message. Thank you for your help.

[#6 · Accepted solution]

@GreatToHearFromYou @dmcaylor There is a known issue being worked on right now which casues IE not to validate a Microsoft signature on a dll shipped with Edge. If you are affected by this bug, you will be find a Microsoft certificate in the "Trusted Publishers" folder in certmgr.msc that matches the one Edge is being signed with.  The workaround would be to remove this cert from Trusted Publishers until we get a fix out. 

[#7]

@Shilpa_SubramanianThanks for the info! This makes me somewhat optimistic. I did find a certificate that matches the one msedge.exe is signed with, I removed it, rebooted the computer and tried IE Mode again, unfortunately it is still popping out into a new Window. However, you mention a dll shipped with Edge and I noticed I decided to remove all the certificates, because the Edge dll's are signed with multiple certificates and after a reboot IE Mode indeed worked again as expected. This is fantastic news!

We will have to wait for the fix though, because those certificates are there because of our Software Restriction Policies and I don't want to break that. I guess anyone that has Software Restriction Policies in place could be affected by this bug, depending on how they have it set up.

Thanks for all your help.

[#8]

@Shilpa_Subramanian 

Great to know. Can you specify which DLL, since there are multiple MS code signing certs in use by Edge?

[#9]

We have noticed the same error as described above.

In another test environment with the same policies, Internet Explorer Mode works fine.

I couldn't find out which certificates might be the cause.

[#10]

@MartinSchneeberger It appears to be user certs. I opened certmgr under the affected profile, clicked Trusted Publishers/Certificates, then deleted expired MS certs as well as MS certs with an intended purpose of 1.3.6.1.4.*.

[#11]

@dmcaylor Thanks! I removed the following certificate. The "Internet Explorer Mode" now functions perfectly.

Issuer: Microsoft Code Signing PCA 2010
Serial Number: 3‎33 00 00 02 ce 7c 9a ce 7d 90 5e d2 b7 00 00 00 00 02 ce
Thumbprint: ‎b1 06 07 fb 91 47 00 b4 0f 79 46 10 85 0c 1d e0 a2 15 66 c1

[#12]

@MartinSchneeberger @dmcaylor 

Thank you for finding the offending certificate, and I can confirm that IE Mode is working again after removing this certificate. However, in our environment we've added this certificate to the trusted certificates through GPO, so that Microsoft Teams (which shares this certificate) can run. Our Software Restriction Policies do not allow programs to run from the user profile folder (or anywhere else but the 2 Program Files folders), unless we trust the certificate. Unfortunately Microsoft installs and runs Teams from the user profile folder, thus we need this certificate to stay in place.

So, even though this is a great find, this is unfortunately not a solution. However, now that I know the culprit I will see if we can move Teams to one of the Program Files folders instead, like we have done with OneDrive. But ultimately Microsoft needs to fix the issue.

@Shilpa_SubramanianAny word on a permanent fix for this yet?

Edit: I just did a quick search and even using the Teams msi, it will still install in the User Profile folder. I don't get why Microsoft is pushing for this. Skype/Lync is installed in the Programs Files folder and get updated perfectly fine. Anyway, all the more reason that Microsoft has to permanently fix this issue.

[#13]

@GreatToHearFromYou The fix for this issue will ship as part of the Windows update the week of 2/17.

[#14]

Morning I am running Win10 1709 x64 + Chrome-Edge Stable channel Version 83.0.478.45. The IE mode has stopped working as per discussion. This impacted one account initially, 2nd account used to logon to machine didn't experience issue. Now the 2nd account has same issue. Edge/IE GPOs are asssigned to machine. I tried removing the cert with matching serial number, however I still see issue.

[#15]

@LeeW78 

Please try latest stable Version 83.0.478.54. Perhaps this will help.