You don't have a recent working save that you can revert back to?
There is a checksum value stored in the save file. If the data for the save is different when loaded than the checksum, the error message is triggered. There is no way to tell what changed, if it will have an effect, or if it does, how severe it would be, without getting someone to examine the save (and even then, if it is not something which would be identified by the debug version of the game loading the save, it may not be possible to track down).
If you email supportdos@larian.com, with a brief description (or link to this topic) and the report.zip file (or a Dropbox or Google drive link, etc) generated by the
D:OS EE Analysis Tool (for Windows), I'll get someone to look at the save.
Extract the zip file somewhere and run the AnalysisTool.exe. When that loads, browse to the install folder (if it is not automatically detected), optionally run the tests first, and then generate a report (it will be saved in the same location as the Analysis Tool).
The report will contain system and game information, as well as your saved games. To reduce the file size, you can delete all but one of the saves from the zip.
