Please navigate to C:\Windows\Assembly and locate Microsoft.AnalysisServices.AdomdClient.dll to check the version number. For 2008 R2, it is 10.0.0.0 required. If no 10.0.0.0, install it by download Microsoft® SQL Server® 2008 R2 ADOMD.NET and running Adomd.NET from:
go.microsoft.com/fwlink/?LinkID=188441&clcid=0x409 (X86 Package)
OR
go.microsoft.com/fwlink/?LinkID=188442&clcid=0x409 (X64 Package)