@Timbercat1 please end the world file you can't save.
@Muhvi - Mhvi Please send the player file you can't save, as well as any instructions on how to reproduce the issue.
Does it happen if you just enter a world and then save and quit immediately?
Do you need a certain item in your inventory or...
@PyxelatorXeroc Please try the attached build with the same `-logerrors -logfile` launch options.
To install, open the zip and replace the Terraria.exe in your steam installation directory with the one in the zip.
Then send me a new log file.
If you'd like to work through this issue more...
I never really worked on Forge. I talked a lot to forge devs, I made a few suggestions, a few pull requests, and I've been around since it started, but Forge was always made and maintained by people with more experience, and a larger project scope than me.