Hi Neha,
There is many reason for this error but it's exactly difficult to see full log.apply this tips if you still not applied .
1) Clear meta data cache from more options.
2) Run program UJA_REFRESH_DIM_CACHE from transaction code SE 38
3) Are there more than one hierarchy use in data access profile?
4) Check the error log from BW SLG1.(It help you find exact route caused of your problem)
Thanks
Khokan