The issue is regarding thread, where if the window is being called in the main thread, you might have to add the attribute to the main method. I have resolved these issues before.
Relevant Skills and Experience
c#, vb.net, xaml, .net
Proposed Milestones
$5 USD - Analyze the main thread
$5 USD - See the reference to and from the main threaded method
$15 USD - Make single-threaded apartment where necessary to solve the problem