Issue:
   Error message is displayed when trying to open a Unity Pro project.

Product Line:
   Unity Pro programming software

Resolution:
  -  Is the project open in another session of Unity?
  -  Go to the Windows Explorer. Right click on the project file and verify that the 'read only ‘ attribute is not set.
  -  Is the Unityxl.ini file attribute set for ‘read only’?
  -  Go to Tools – Options – Connection. Make sure that programming mode is set.
  -  File - Open.  Make sure that 'read only mode' is not checked in the 'Open Options' in the lower left corner of the Open box.