Quick one today:

Earlier this interesting error occurred in our environment. When we tried to use DAC, we ran into this error:

Dedicated administrator connections are not supported. (ObjectExplorer)

For a few moments it seemed unsettling. If a DAC connection cannot connect so Sql Server, then we are in big trouble. Upon some contemplation (a.k.a. banging head on desk), it became apparent that there is huge silver lining to this. This error is be design.

When you open SSMS, the pop up window that comes up for connection is for Object Explorer, not query window. DAC connections are not allowed for Object Explorer window connections. Hence the error. DAC is supposed to be used only during rare events; For that it is necessary to make sure the connections are not used for purposes other than the absolute intended purpose. Hence DAC prevents inadvertent connection requests to Object Explorer with a safe error.

Use Database Engine Query to open new DAC connection.

Hope this helps,
_Sqltimes