Can't create new library

[Zelna3]

Server Version#: 4.117.3 or is it 1.32.7.7621 ? I find two numbers depending on where I look.
Player Version#: 1.72.2.3901-b7911c36
Windows Server 2016 Datacenter Edition

Currently I am unable to add a new library to my plex server. The language dropdown is unpopulated and doesn’t allow for the selection of a language, and as a result, the next button is greyed out, preventing me from moving to the next step in the process. I was able to add libraries when I initially configured the server.

So far I have tried:
3 different browser clients
the desktop client
a different computer
turning off VPN on the server
turning off VPN on the client
restarting the server
restarting plex
re-scanning the existing libraries
optimizing DB
cleaning bundles
re-running the plex installer

The only thing I can think of that is left to try is to completely uninstall plex and reinstall plex, which would be very disappointing, as I only configured this plex server earlier this year.

What would you recommend?

[Zelna3]

This is what it looks like when I try to add a library. Clicking on that dropdown does nothing, as the languages are not populated. Languages work fine in any other menu that references languages.

[smorrell2016_gmail_com]

Did you get any help on this issue, as I am experiencing the same thing.

[OttoKerner]

Stop and restart Plex server. Then try again, using the hosted web app in a regular web browser without any add-ons.