Apologies, we are digressing from the topic and I feel it is my fault ^^'
LoopZoop, from your explanation could be that your drive got corrupted in some way. Once data is affected, not much can be done generally.
As a first step, you can run some check to see if it can confirm it. Honestly, I am not sure of its fiability, but on Windows, open a command window and use "sfc /verifyonly" to run some preliminary checks.
More info:
https://technet.microsoft.com/en-us/lib ... 84577.aspx. Check teh scannow and scanfile options, can be useful.
If it confirms that data is corrupted it may show the file and thus confirm it is affected.
If no error is show, then we are back to square one and could be an issue. I will try to load the save file in a clean installation later and see what happens.
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Now, digressing again, the ZFS is a filesystem not available on Windows and a perfect solution should com from the filesystem. But probably something easy could be done from OpenMW side, maybe just keeping a backup of the last saved file when overwriting, or attaching a md5 hash to the safe file in some way.