Release group ' ' not allowed

What causes this issue?

You have created a release group with the key ' '. This is not allowed
because errors may arise during the determination of the
<DS:GLOS.3526BFF3AFAB52B9E10000009B38F974>release strategy</> as a
result.

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?

Delete all release strategies for release group ' '.
Delete all <DS:GLOS.3526BFF1AFAB52B9E10000009B38F974>release codes</>
for release group ' '.
Delete the release group ' '.
<zh>Note</>
Delete the release strategies and release codes before deleting the
release group, since these strategies and codes are subsequently no
longer visible.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.