Diagnosis
You looked for, but did not find, data elements for domain &MSGV1&. Thereason is probably because all data elements for this domain arealready used in other object types.

Procedure
If necessary, use a data element that does not correspond to the domainof the key field. You can enter data elements with the general search.There is only a check whether the data type and length are correct forthe key part.
You can also create a new data element for the domain.