Hi Olaf
As per the error message provided by you, we can infer that there can be two possibilities for the issue.
- There is no system alias defined in your system landscape
- The user which you are using for testing doesn't have permission to access
the system alias.
Kindly refer to the below KBA - 2030655 - Portal runtime error "System Alias is not defined or permission denied for this user" and carry out the steps given in the resolution part of it for two of the above expected scenarios.
Regards
Santarshi Samanta