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Does anybody has a similar problem? I cannot save the game - it always show the same ingame communicate about save failure. Of course i'm trying to save outside any mission and after tutorial.
This question / problem has been solved by krzimage
If you are using Bitdefender, the game might be detected as ransomware.
Try the solution from the Bitdefender website:

"1. Click the B icon on the left side bar of the Bitdefender interface.
2. Click the VIEW FEATURES link.
3. In the SAFE FILES pane, click Application access.
4. The apps that have requested to change files in your protected folders are listed. Click on the switch next to the application you are sure is safe, and set it to Allow."

This also fixed my problem with not being able to create a Titan Quest character.
Big thanks krz! Bitdefender was the problem.