EOF means "end of file" - which means that when trying to load a file the mentioned file is too short and missing data.
if this happens on saving that means the program checks the existing saves before truly saving, because that error cannot happen in the save process itself.
And this means either the existing saves were damaged, or are now incompatible due to script changes.
please make a very simple test: delete (after backup) all existing saves in your project, then try again.
if it works from now on, the old saves simply became incompatible due to a script you added, and it will work with the new saves.