Diagnosis
Field name &v1& is not known in the field catalog of the interactionlayer of condition maintenance. The field catalog of the interactionlayer can be filled via method ADD_REMAIN_ATTRIBS_ITEM_ALV for BAdI/SAPCND/MNT_USAGE.

System Response
The selected action cannot be executed.

Procedure
Inform your system administrator.

Procedure for System Administration
Inform your responsible support organization.