You cannot create a revision level here

What causes this issue?

You wanted to create a revision level.
However, this is not possible in the following cases:
When scheduling the creation or changing of a material
In display mode
If revision level management is not active

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?

Check your data.

Error message extract from SAP system. Copyright SAP SE.