Hello;
You may get the error "rfc communication error with system/destination" while you import one of your transport requests from one SAP system to another as below image shows:
Solution:
To fix this error go to client 000 --> run transaction code STMS --> overview --> systems
Extras --> reset user TMSADM
Extras --> Generate RFC destinations
This will fix the error.
Hope this was helpful.
Best Regards
~Amal Aloun