When creating a portable company file, you see:

You may not have sufficient permissions to create a portable company file from this computer. Please try creating the portable company file from the server: (SERVER_NAME).
Solution 5: If you are converting a company data file to a newer version of QuickBooks over a network, or creating an Accountant’s Copy or portable company file over a network

  • Copy the company fileto a local hard drive (like the C:\ drive) to perform the operation and then copy it back to the original location when you are finished

http://support.quickbooks.intuit.com/support/Articles/SLN40385