Unable to make the file read only in SOS

[Spock]

Sometimes when I do a "Get Latest Version" on files that needs to be updated in SOS, I get the following error message:

File Name - Unable to make the file read only.

I have this problem since I upgraded from version 3.5 to 4.1. If this is a bug, it doesn't look like it has been fixed in version 4.1.2.

What is the problem? Am I missing something?

Thanks