Does your error go on to mention a plugin called "Shaz_TileChanger.js"? If so, it can probably be fixed with the "Old Save Compatibility Patch (For saves from 0.34 and older)" patch from the download folder. Do you recall what version your current save was originally from? Because if it is from version 0.34 or older then it's almost certainly the issue solved by the patch I mentioned. There was a plugin added in version 0.35 that caused issues with older saves, but using that patch makes your save compatible. Probably worth a try regardless, but if that doesn't fix it then if you could upload a picture of the full error report that would help a lot, thanks.