The System Requirements Check was unable to write files to a mapped drive.
In-Application tests need to store the documents for each assignment on your computer. You can get this error when a drive letter is used to map to a folder, usually the user's temporary folder, and that folder is not writable.
The actual directory used should be listed in the system requirements log. Please check the permissions on your directory and try again.
If you need further help, please copy the logfile and send it to PSI support. Either use the button on the system requirements page or copy the text from the java console. Read this if you don't know how to open the Java Console.