BUG #14382: System.TypeLoadException: Failure has occurred while loading a type

The following bug has been logged on the website:

Bug reference: 14382
Logged by: Jitendra Mali
Email address: mali(dot)jitendra(at)tcs(dot)com
PostgreSQL version: 9.2.13
Operating system: Red Hat Linux 7.2
Description:

MVC 2 Web Application is deployed on Red Hat Linux 7.2. It is using Mono
4.2.2 and Postgres 9.2. Postgres and web app are present on same linux box
and trying to access app from same linux box.

pg_hba.conf is configured with below settings:

# TYPE DATABASE USER ADDRESS METHOD

# "local" is for Unix domain socket connections only
local all all trust
# IPv4 local connections:
host all all 127.0.0.1/32 trust
host all all 0.0.0.0/32 trust

And postgresql.conf is configured with below connection setting:

# - Connection Settings -

listen_addresses = 'localhost'
port = 5432

After modification in above config files, database is restarted.

When web app is calling NpgsqlConnection's open method, below error is
surfacing:

System.TypeLoadException: Failure has occurred while loading a type.
at Npgsql.NpgsqlConnector.Open () [0x0002b] in
<66e0c39290f143458641d7ea98ad7557>:0
at Npgsql.NpgsqlConnectorPool.GetPooledConnector (Npgsql.NpgsqlConnection
Connection) [0x0015f] in <66e0c39290f143458641d7ea98ad7557>:0

Deployment folder's bin folder is containing Npgsql.dll (Version 2.2.5.0 and
Mono.Security.dll (Version 2.0.0.0).