BUG #15165: The application server could not be contacted

The following bug has been logged on the website:

Bug reference:      15165
Logged by:          Qutubuddin Mohammad
Email address:      qutub2108@gmail.com
PostgreSQL version: 9.6.5
Operating system:   windows 7
Description:

I use PgAdmin to connect to RDS instance for Postgres Versions 9.4 to
9.6.5

I installed PgAdmin Ver3 and uninstalled it because it was throwing error
server cannot be reached, Now i cannot even access PgAdmin ver2.1, can you
please help me out.

Fatal Error:
The application server could not be contacted.

Thanks,
Qu, Mohammed.