ARAS 31 soap-env:server authentication failed for admin authentication failed for admin

Hai,

We have upgraded to ARAS 31 from 12. The migration is in progress. While login from application Its working fine. But while login from web API we are getting an error "soap-env:server authentication failed for admin authentication failed for admin"

We have tried to give the password in MD5 hash format for username admin.

But the error not yet solved. 

can anyone help us on this?

Thanks in advance,

Salini