WPF multi-thread UI is not thread-safe

_This issue has been moved from [a ticket on Developer Community](https://developercommunity.visualstudio.com/t/WPF-multi-thread-UI-is-not-thread-safe-/10531948)._

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\[severity:It bothers me. A fix would be nice\]
Hello,

We have WPF project where there are a 3 UI windows, each one runs on its own UI thread.
On project startup, the threads are created and by the way the 3 windows are created in parallel.

We noticed that the method **InitializeComponent()** is not thread-safe and causes an exception in the method **CleanUpRequestedStreamList()** within the file **PakageParts.cs**

In the following screenshot, we see that **\_requestedStreams.Count = 1** so the variable **i** should start from **0** but its value is **1** which means another thread modified it.


Is there any possibility to support multi-threaded UI in Wpf?

Thanks!

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### Original Comments

#### Feedback Bot on 12/4/2023, 07:18 AM:

(private comment, text removed)

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### Original Solutions
(no solutions)