Running Edge 85.0.564.44 on Windows Server 2019, August 2020 update level. Sometimes users are getting the message:
To open this page in internet Explorer mode, reinstall Microsoft Edge with administrator privileges.
This error seems weird, because we are using the Edge MSI, and Edge is installed in Program Files. Also when they re-logon or kill all iexplore.exe processes the error is gone again.
The eventlog shows a related error message as well:
[12372:12800:0909/132815.123:WARNING:web_contents_internet_explorer_tab_host_observer_win.cc(207)] Creation of Internet Explorer mode tab failed: 3
I've searched for it, but no results so I guess I'm the only one. I can re-produce this. We are running an intranet site with infopath links in IE11 mode. So users launch Edge, open the infopath document. Close it again, close Edge. Start Edge again and there is the error which can only be fixed by killing iexplore.exe.
Another issue, which might be related (or not). Is when we open an infopath document from Edge, and infopath opens and is in the foreground, Edge is completley frozen. You can't click anywhere. Until you minimize infopath, then you can work with Edge again.