Excel Data Refresh error to Analysis Services 2008

One of my developers was having an issue refreshing data using excel services in browser to Analysis Server 2008. It seems he added PowerPivot for excel that change some default connection string setting in excel. His connection string was generating “provider=MSOLAP.5;…” Which is not listed as a trusted provider in Excel Services.

Once i added MSOLAP.5 as a trusted provider, data refresh worked in browser!