Unable to Connect to Repositories

Hi Experts,

I am using MDM 7.1 version(build version 7.1.09.286) with ORACLE database. I was able to connect to repository previously and all of a sudden unable to connect to any of  the repositories with different users. I getting error  "repository connect fail Error:invalid object state".(Attached screenshot). Please suggest me the solution If anyone faced same problem

I have referred the forums and based on the inputs, performed below activities,but still problem exists.

1. Reset the Database password
2. Restart Database server
3. Restart MDM server
4. Mount the MDM Server
5. Load the Repository.

Please advise

Regards

Sunil