You need to just have files selected if you want to check if any are marked as read-only. Since Vista, I think, MS change the behaviour so that if a folder is selected, the Properties will just put a square in the attribute box, indicating that didn't check the folder contents. You can click the box to cycle through read-only (checkmark), not read-only (empty) and unknown (solid square), and for the first 2, have the option to apply the changes to the folder, subfolders and files.
If you still have the old save, could you zip it and email it to supportdos@larian.com, with a description of the problem? Someone said yesterday that mailbox was full, so you could use the general support address instead: support@larian.com.
The
D:OS support tool would create a report.zip file containing system info, crash reports and your saved games (to reduce the file size you could delete the new saves and any old working saves from the zip, since they are not relevant to the problem).