Can you please try to re-initiate the application message?

we have tried that a few times and still no luck 

Sorry to hear that.

Due to the short timeframes there are with CIS monthly returns, I suggest raising a case to make sure a return can be made in time.

@Ieva Rituma  - I have a case already logged but just wanted to see if anyone else was experiencing the same issue 

I am having trouble too but another error message with a Test Submission of CIS Supplier verification and CIS Monthly return. I get:

Authentication Failure. The supplied user credentials failed validation for the requested service.

I am doing a test submission and I am sure the Username/Password is correct…

I think I saw something similar to your message and it was to do with the IFS Connect Routing Rules or Routing Addresses...