shankbond 0 Light Poster

Hi,
I am making a web application which uses webservices. The problem is that whenever I reopen my web application after closing it, I get an error message supplied as an attachment.


Then I have to delete and add webservices again to make the project back in working state.
This same problem also occurs when I leave my project in idle state for long time.
How can I resolve this error?
Any help shall be appreciated.