Hi Balaji,
Indeed this is a very generic error message as mentioned by Subhash.
You can record the log files of AO 2.0 referring to SAP note below:
>> 2129389 - Analysis 2.x Log Files
The logs should contain details regarding this error. Make sure the setting "Enable BW Server Tracing" is checked in Support Settings of AO (i.e. File > Analysis > Settings) before reproducing the issue.
Then you can also take a look at the trace in backend (transaction RSTT).
You can also create an incident under component BI-RA-AO-XLA along with a document containing the steps to reproduce the issue, in case you need further help.
Cheers,
Filipe Zeuch