"Message loop has not started yet" problems

Good morning.

First of all, thank you for your great work! :)

I'm using NTwain in a project; in this project there's a C# .NET 3.5 assembly (assume is "Client.dll") that is called by 3rd party software. In Client.dll I use a WPF window to show acquired images.

The "scanning layer" of my Client.dll is a protocol agnostic layer; I use an ISIS "driver" and a "TWAIN driver" (NTwain, of course) and I load one of the two by reflection at every scan, depending on configuration passed to Client.dll from my 3rd party caller.

On my TWAIN driver I create and destroy a TwainSession at every scan, disposing it as recommended; all this stuff (creation, use, dispose) is made at every scan in Client.dll.

So, now the question: I'm exeperiencing a weird behavior in this scenario: the first scan runs smoothly, the second one throws "Message loop has not started yet" exception; I'm using 3 Canon devices (P-150, DR-2580, DR-9080).

To benchmark my NTWain driver I wrote a Winforms app that does the same thing Client.dll does, and using it there are no such problems. Even your WPF works.

Have you some suggestions? I think is something related to Dispatcher, but I'm a WPF noob, unfortunately. Client.dll have to use it so I need to get it work in WPF.

Thanks, Nando

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