Matrix Reports no calculating

Matrix Reports no calculating

Our activity reports, which have been working just fine until this am, are now showing 0 for activities, if you change the report type it pulls just fine.  Can you help, and explain why this has happened.  The fields I need are not eligible for column headers, please help.  Doesn't matter how you configure.

__ Activity Modified Time Activity Modified Time Activity Modified Time Activity Modified Time Sum of Record Count
Subject 2014-12-01 2014-12-02 2014-12-04 2014-12-05  
call 0
Call 1 0
Call 2 0
Call 3 0
Call 4 / Pause for Gift Email 0
Call 6 0
Call 7 0
Call 8 0
Conversation 0
Final VM / Email forward 0
Intro Call Scheduled 0
lvm 0
LVM2/PermyVM Email 0
LVM3/PerMyVM 0
Send email 0
Sum of Record Count 0


Leah Edwards