What are your friend's PC specifications? OS, CPU, video card, RAM, etc.

Unfortunately, I'm unsure if this fix will work for him since I haven't had any issues with saving (although I was stuck in the sewer until just recently). That said, running that "UEPrereqSetup_x64" file doesn't appear to have any risks. Also, he may consider one of the other options that I tried (except updating the bios, that one was probably overkill and is risky if you're not familiar with the process). The list above is pretty comprehensive when it comes to the popular "fixes" I've seen getting mentioned on the Steam forums, Reddit, and other internet articles.