I don’t know quite how widespread this issue is but it’s something I have had some trouble with on and off since I updated my OS to Server 2019 last year. That said, I’m not saying this is an issue limited to this OS; indeed I have seen it on other OS’s too.
The issue is this : Word will ask you to sign in and after entering your email address, it will freeze for 5 minutes before returning you to the (unlicensed) state you were previously in. Similar with Outlook – you enter your email address and the white password box appears but appear blank and freezes for 5 mins before returning you to the previous (unlicensed) state.
There are a number of things that you might try (including full uninstall/reinstall in desperate cases) but I’ll show you a couple of things you should try before doing this (or calling Microsoft, as they will ask you to do this too, more likely than not).
First – Remove previous license information
- Open C:\Program Files\Microsoft Office\Office16
- From a cmd prompt, type cscript .\OSPP.VBS /dstatus
- This will give you a list of previous license keys used. Remove all these using cscript ospp.vbs /unpkey:<5 digit code>
Second – (if the above doesn’t work) Disable Modern Authentication.
Open up regedit and navigate to the following key:
Add a new DWORD value called EnableADAL with a value of 0.
Open up Outlook and it should now present you with a password window you can actually use. Word/Excel etc should open up as expected.
For a little more info on Modern Authentication in Office 365 see here.