Unable to create or resume worlds

Please verify your game files via steam. If that does not solve the issue then please follow the steps in this help article. I'd suggest starting at #3
https://support.klei.com/hc/en-us/articles/360029882171-Getting-a-Unable-to-write-to-files-in-the-config-directory-Error-Message

If neither of those help, then please post your Master and Caves server log files. You can quickly jump to them by clicking the Manage World button on the host game list screen then Open World Folder.

these are the log files

server_log.txt server_log.txt

restarting my computer seems to have fixed it. may have been a problem connecting to steam

From the logs I was going to suggest to restart steam or your computer. I'm glad you are back to playing!