At least one incorrect task exists in the template message

What causes this issue?

At least one item of the template notification contains errors. The
cause could be, for example, that the code entered in the item is not
active.

System Response

The system terminates the creation of the notification with template.

How to fix this error?

Check why the template notification contains errors and, if necessary,
correct them.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.