SAP Message 6A757 - The authorization group '&' is not valid

Diagnosis
This authorization group is not permitted for the object type you wantto process (for example, business entity, rental agreement, and so on).
The authorization groups that can be used for each object type aredefined in Customizing.

System Response
You cannot assign the desired authorization group to the object youwant to process.

Procedure
Verify your entry and correct it if necessary.
If your entry was correct, contact your system administrator.

Procedure for the system administrator
Check and correct the settings for the authorization group inCustomizing as required.