When I tried to create a new project with a new installation, I received an error message that the file I was trying to create does not exist. Naturally, there are not a lot of options for how to proceed at this point. I had a sudden realization (only because this has happened before with other software) to check my notifications, which only periodically appear, and I saw that Windows Defender was blocking write access from KiCad. Once I allowed this access, KiCad created the project.
Perhaps there’s a way to detect if write access is blocked? I suppose the Windows file creation dialog is fairly standard, but if there’s a way to customize it to suggest disabling any programs that will block file creation, that would probably help a subset of users.
I have never seen that, I think, but we definitely need some more documentation about this or some other way to understand the underlying issue some more.
I’d like to add that a similar issue occurs with BitDefender. Its a really annoying feature of BitDefender that tries to stop against Ransomware when it detects an application trying to edit files.
For BitDefender I just disabled “Ransomware Remediation” and that worked. Alternatively you can add KiCad to its list of exceptions, but you need to add every *.exe in the KiCad \bin folder that might write to files.