I assume this issue will be related to access privilleges or some specific security restrictions.
Please check the SoapUI logs if you can spot some errors. I would expect you could find a message that the project file is unavailable for SoapUI.
The SoapUI logs are accessible from SoapUI or in the SoapUI/bin directory.
Also you can try to save the SoapUI project files in your home directory (e.g. on Desktop) and check if it resolves the issue. The locations you have mentioned might be considered as protected byt your security settings.
Best regards,
Karel
