There are a few different areas to check in this case:
1. Check that the User (ASUS) and Password (ASPW) supplied are correct or Trusted Connection is selected (ASTC).
Ensure the User is valid as a login to the JIT Application Server.
Double-check the User and Password was entered correctly.
Check the User and Password values in the application start file on the Client PC.
2. Check the Host Route entry exists and is correct in the lroute.dat file using the LANSA Communications Administrator.
Ensure LANSA Communications has been deployed to the Client PC.
An appropriate entry should exist in the lroute.dat file on the Client PC. Check the LU name, Qualified Name and port number are correct.
Check the listener is started on the JIT Application Server and listening on correct port.
3. Check the network configuration
Verify the IP Address being used
Correct any network errors.