ASP.NET Cannot evaluate expression because a thread is stopped at a point where garbage collection is impossible

I have a weird problem, I get an object from my DB, like this:

var use开发者_如何学Pythonr = BLL.Managers.Users.UserTmpManager.GetUser((int)customerID);

when I debug that code, and expand the user object, for each property I see the error as I mentioned at this topic's title. What causes it ?

unfortunately, it is still not being resolved, as I thought at the beginning..

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I got this too, when I hit a NullReferenceException from a 3rd party control.

In this one case, I found that if I set a breakpoint before I hit the exception, I could then single step through the rest of the code without seeing the problem.

No idea why, but this worked for me - in this case at least.