Hi Varsha,
For me it works only at time, its totally weird Image may be NSFW.
Clik here to view..
May be you can restart the device and try or update the EPM to the latest or press that try again button (once it worked for me that way Image may be NSFW.
Clik here to view.) . Check out the below URL, it explains about the different MOB errors you get.
http://help.sap.com/businessobject/product_guides/boexir4/en/410_mobiPad_errmsgs_en.pdf
I have raised a OSS message for an issue which i am facing in my BPC 10.1, may be their solution might fix this. Will update here if its fixed.
Regards,
Prithivi Raj