Hello Marcos,
As described at note 1793251 - FAQ: Known problems without a specific SAP
1. You are using Central User Administration (CUA). When you try to display or change certain users in SU01 or SU10, the dump GETWA_NOT_ASSIGNED occurs in the ABAP program "SAPLSUU7, SUSR_USER_LOCPRO_BUFFER_FILL.
Reason: There are inconsistencies in the table USL04, that lead to the dump specified above or missing entries in the table USRSYSPROF (text comparison for profiles from child systems) since the correction from SAP Note 1663699.
Which provides you to this note http://service.sap.com/sap/support/notes/1663699
BR,
K.