Client Web Service Error: Cannot access a closed file

Problem

Webservices and DropDowns fail to respond, sometimes intermittently. When this happens the following error is found in the EventLog of the ClientWebService server:

System.ObjectDisposedException: Cannot access a closed file.

Solution

Check how much free disk the server has and free up more disk space if neccessary.

Also check the memory usage on the server and consider increasing the amount of RAM.