When trying to EFILE, Internet File or NetFile, the EFILE Session window does not respond after some time. The error reads EFILE Session (Not Responding).
Normally, the transmission window will establish a connection with CRA or RQ within a few seconds, even if it displays a Not Responding message.
Resolution
Refer to the article Receiving 'Webservice Unavailable' error when EFILE, NetFile, or transmit return to resolve the issue.