See the question and my original answer on StackOverflow

Your trackback shows a -2147352567 error code. This is DISP_E_EXCEPTION, a very generic COM exception. It wraps a -2147215865 error, which is also 0x80041607, which is also QUERY_E_TIMEDOUT.

I use this free website tool - I made it - to find errors and other constants like that:

So, in fact, they all report the same timeout error.

You can increase ADO timeout as described here: Having Problems With SystemIndex (I Love It But Can't Make It Work How I Want)

or you can remove it completely, with a code like this:

conn.CommandTimeout = 0