When using a proxy on a Dollar Universe node v5.6 you need to add a specific definition to the proxy file for uniexp and uniimp to work.
If you don't add this definition, the command will not extract and the following error will appear in <DUAS>/exp/log/universe.log:
/u_traite_req_io_prox/000000000 - username (UNI,,UVMS,UVMS) not in proxy table
Use the following command to add a definition to your proxy file:
$UXEXE/setproxy UNI "*" "UVMS" "UVMS" "<user>"
where <user> corresponds to the parameter "-login <user>" that you are using in uniexp or uniimp
Then reload the proxy definition:
...or restart the DUAS instance