Java Script error on the Controller

rupaln

I am getting the following error, midway while executing my script. Its forcing me to close and reopen the controller to execute the same point... Any idea on what's causing this?:
Error:"The callee (server(not serving application)) is not available and disappeared; all connections are invalid. The call did not execute."

Thanks,

darsh_mehta

I am facing similar issue, error.

Code Snippet:
_popup("top")._setValue(_textbox("username"), $strUID);
_popup("top")._setValue(_password("password"), $strUPWD);
_popup("top")._click(_submit("Login"));
_wait(30);
if(_condition(_popup("top")._assertExists(_select("companyregistry"))))
{ XYZ }

At the IF condition it returns error:
The callee (server [not server application]) is not available and disappeared; all connections are invalid. The call did not execute.
(SERVER-URL/bp/nav/main/user:38)
saveCondition("__lastConditionValue__0", _popup("top")._assertExists(_select("companyregistry")))