Other infotypes exist; no change allowed

What causes this issue?

Other infotypes have already been created for this business event which
cannot be maintained with this transaction.

How to fix this error?

Delete the additional infotypes that you created. You can then change
the business event. If you still need the information you have deleted,
you must add it again.

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

Error message extract from SAP system. Copyright SAP SE.