What could be reasons a WPF app would pin the CPU and lock the app on some computers but not others?

Question

Stumped here. Posted a similar question before. We have a pretty large WPF app that on some machines runs great, but on others, all of a sudden, one of the CPU cores gets

Answer 1

Found it!! Turns out there's a bug in .NET 4.0 regarding UI Automation and the changes MS introduced. Here's the info, and the fix! (Note: Even if you call MS, they will send you a link, but it's always a broken link. I managed to track this down manually.)

Note: Their article talks about a specific case that causes this behavior, but if you google around, you'll see tons of issues around hangs related to those DLLs. The latest is they're promising a fix in the .NET 4.5 runtime (from a MS post on this issue.)

Here's the KB article...
http://support.microsoft.com/kb/2484841/en-us

...and here is the actual hotfix.
http://archive.msdn.microsoft.com/KB2484841/Release/ProjectReleases.aspx?ReleaseId=5583

Answer 2

Since you seem quite to lack options, i would advice to make a new project with just most basic ComboBox in the Window, doing almost nothing. This should work (check :-) ). Then you add features one by one in the ComboBox and test, for instance when you add command, start with empty one. Do this until it 'breaks'. So you know which feature is the culprit.
You didn t say if all was working with software rendering.

Answer 3

Crappy video driver? Pull two machines - one where it happens, one where not, and start analyzing differences. Could be hardware defects, bad video drivers, anything in that area. WPF uses the GPU to render if one is there.