Invalid PBT server group name: &

What causes this issue?

The system tried to initialize the environment for processing parallel
RFCs using the function module SPBT_INITIALIZE. The server group name
specified was found to be invalid. The server group name describes a
group of servers on which the parallel RFCs should be processed.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

You can use Transaction RZ12 to determine which PBT server groups are
configured in your system. You should only use one of the server group
names listed there to process parallel RFCs.

Error message extract from SAP system. Copyright SAP SE.