Empty Service Level Tracking Summary Report (OpsMrg 2012R2)

Hello,

i have a Problem with Service Level Tracking Summary Report in OpsMgr 2012 R2.
Since we updated to OpsMgr 2012 R2 all SLT-Reports are empty (mostly) or show only a grey Ø.

I can´t find any error, i also tried different groups and distributed Applications (that worked before)

Can anyone can give me a hint where to look or what´s the problem?

Thanks,

Michael