After reinstalling from SW_DVD5_Office_Professional_Plus_64Bit_English_-2_OfficeOnlineSvr_MLF_X21-25538.ISO as described in TechNet, All the office applications worked OK except Excel.
The error was "We're sorry. We ran into a problem completing your request. "
and in the preview "Sorry, we're having a problem showing this workbook."
Details
We don't know exactly what happened, we just know that something went wrong.
the same ISO was used in DEV environment with HTTP allowed and no errors found. Anyone had the same issue
Ofer Gal