Unknown user error on forward to SAP via ITSM

Hello Gurus!

I'm having the following problem.

We have a new customer, everything is set up like for the other customers that doesn't have this problem.

When we try to forward an incident over the SolMan, SAP Collaboration tab we get the error, Unknown user

It doesn't matter which user we use, it's always the same message.

General prerequisites:

- Working RFC destination to SAP (normally SAP-OSS) -> OK

- Your user is mapped to a valid S-User in transaction AISUSER -> the used S-User is a Super Admin on the customer SMP

- The transaction needs the following text types for the initial sending to SAP: Description, Information for SAP -> OK

- Valid SAP system in SAP Attributes to which the transaction is related -> Systems are visible in the customer SMP therefore they should be valid

- A valid SAP component is assigned to the incident -> OK

The SolMan is 7.1 with SPS14 and we are VAR Partner of the mentioned customer. The installed components are in the attached txt file.

I already checked all the users involved in this process, everything looks fine and there are no runtime errors in the system.

Had anyone seen something like this ?

Thanks,

Tamás