BPC 7.5 NW "Empty XML Results" error.

Dear Gurus,

We have problem in our current BPC 7.5 NW system. When refreshing Excel report users get an error as "Empty XML results" 

So far, I have found couple notes and some forum topics but none of them help.
(1793940 - Empty XML ,  1760900 - Empty XML )

I also have cleared all temp folders,etc.

When I go to BW side, I can not find an error in ST22 either. However, I found a job (BI_PROCESS_LOADING) which is canceled in SM37 after we got this error but before it was working fine.

PS= I can not found this error in ST22.

Any helps?

Thank you in advance!