Path is read only. Select another path

Hi There,

I've created a project in Netsys   CWS  which is a multi level project. I closed the project and when i come to re open it I get the error above. I'm using windows path/ file method, and the project is in a location which isnt protected or write only. 

The green tick is available and the window shows a project is there with the correct number of floors etc.

Have I set up the system wrong or am i doing something wrong??