First, we notice that you posted a very similar thread earlier back in February: When generating screen saver, getting error Error saving Icon file. Err=104 IOException
Did you ever solve that issue? You mention using CrowdStrike in that thread, and in this thread you say
This is most likely the problem still.
Please note: iScreensaver always builds to a temporary folder, and it sounds like your security team is blocking that build location.
For the solution, see here: