can't save

[OmarXZ5780]

Describe the bug

i was using this tool to add sprites to pizza tower but when i tried to save it. It kept saying this

Reproducing steps

i open the pizza tower data which sends me to undertale mod tool. I made sprites and a background so i go to scripts, resource repackers, import graphics and i put in the sprites graphics. it imports but i want to save it. and then the error pops up

Setup Details

i have GUI window latest release isBundled true isSingleFile true my os is windows i was modding pizza tower

[Jacky720]

Does this still occur on the current bleeding edge?

[Miepee]

Going to close this for now. If someone confirms that this is still reproducible on current builds, please reopen the issue.