System &1 not activated

What causes this issue?

An error occurred in the TMS communication of the following SAP system:
System: <LS>&V2&</>
Function: <LS>&V3&</>
Error: <LS>&V4&</>

System Response

The function terminates.

How to fix this error?

Activate this system with transaction STMS.

Error message extract from SAP system. Copyright SAP SE.