Diagnosis
You are using your cursor to move through a list of time periods andhave reached a time period for which there are no (more) statistics onthe MONI performance database. If the statistics used to be in thedatabase they were probably deleted by data reorganization.

Procedure
To keep data for longer periods, call Transaction ST03 and chooseGoto -> Parameters -> Performance database . Then chooseGoto -> Modify parameters. Change the residence time and saveyour entriese by choosing Edit -> Save changes.