Error - "System.NullReferenceException" when connecting. (4270257)

When user enters the connection information and hit the create button, Toad throws the following error.

Exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.

Possible corruption with the connection history file.

Issue with a long server name. Microsoft SQL DMO only allows max 32 char in server name. In version 2.0 Toad bypasses the issue, but not in 3.0.

WORKAROUND 1:
Go to C:\Documents and Settings\\Application Data\Quest Software\Toad for SQL Server and find the connections.xml file. Rename this and start Toad. This will remove your connection history and settings (including any saved passwords).

Start Toad again and reconnect. The history has been removed and new connections for each login will need to set up again.

WORKAROUND 2:
Try to connect without the domain name so that the whole string in the Server field can be shorter.

For example if your server name is "company.prod.corp," drop the ."prod.corp."

STATUS:
Issue fixed in version  3.1. The latest version of  Toad for SQL Server  can be downloaded here.