Group have the access but not able to access the database?

Hi All,

I am facing the different issue in my environment .

we have grant the read and write access to one group on database, after that we have added the one user to that group.

now user was unable to connect to database and his get below error....

Msg 916, Level 14, State 1, Line 1
The server principal "xxxx\xxxx" is not able to access the database "testDB1" under the current security context.

Please help me on this issue asap.....

Thanks in advance .....

RAM