Create a new project. Copy each FB/FC/OB one at a time from old corrupted project to new project. If one of the FB/FB/OB does not copy properly, you can fix that by copying rungs.

Once you have the FB/FC/OB, copy DBs and PLC Tags, etc.

Copy the device configuration as well.

All of these copy/pastes work if you set up both TIA software windows tiled side by side. Then you can drag from old project to new project.

Compile and download. If it copies and downloads everything properly, you will have a new project file without any corruptions. If the PLC still has problems, you can restore it to factory defaults and reload.