Stuck in 'Saving World' Screen with only Forge

[lavenderwolf]

Hello!

Everytime I go on "Save World & Quit" Minecraft will show me the "Saving World" screen, and there it stays. I tried waiting about ~20 minutes, before I closed Minecraft via Task manager. (Nothing else worked).
All the Launcher shows me afterwards is the "Error - Game crash - An unexpected issue occurred and the game has crashed. We'e sorry for the inconvenience." So I don't have a crash report, but maybe the log file helps?

I think it's an issue with Forge, because, if I play completely vanilla, it works perfectly fine, and I tried it with only Forge and no other Mods in and I get stuck. 
(Also made a new world were I hadn't used any mods in prior.)
I used the "Recommended  1.15.2 - 13.1.0" Installer. 
I play Minecraft 1.15.2 on Windows 10

2020-02-07-8.log

debug-1.log

Edited February 7, 2020 by lavenderwolf

[FreeFull]

I've ran into this exact issue today. It turned out to be an expired session token in GDLauncher. After logging out of my Mojang account in GDLauncher and logging back in, the issue has gone away.