Dear Raja Sekhar,
The Cause of the issue if i am not wrong -
"You tried to open the database of NAV 2013 R2 with build 36281 but then decide not to upgrade".
Here is what you can do -
(Before performing take a backup of database)
1. Upgrade the client and service with the Update rollup 5 for NAV 2013 R2.
You can download same from mbs2.microsoft.com/.../KBDisplay.aspx
2. Open the database with upgraded build in developer environment, convert it and it should work fine.
Let me know if any issues.