Diagnosis
You want to assign a display block to a list profile. However, themaximum display block from which the fields in the display block werecopied has a different list name from the list profile.
You can only assign a display block to a list profile if the maximumdisplay block and the list profile have the same list name.

Procedure
Ensure that the list profile and the maximum display block are assignedto the same list name.