Error HRESULT E_FAIL has been returned from a call to a COM component

Question

In Silverlight 4 app; what does this error mean?:

\"Error HRESULT E_FAIL has been returned from a call to a COM component.\"

It

Answer 1

The IIS App Pool has to run as an account that has query access to the Team Foundation Server. This fixes the problem for me.

Answer 2

In my case it was, when I tried to import database into the SSDT project, but this database already was in project, but was empty. I've just updated my project with Tools -> SQL server -> New schema comparsion. Source - database, target - project. Compare - update.

Hope it helps to someone

Answer 3

I had this error in my xaml page and there were no syntax errors. Cleaning and re-building the project solved my issue. fyi...

Answer 4

I received this error recently in VS 2013 for a Silverlight 5 project. None of the above worked for me. Oddly enough, it was a threading problem (normally I am used to an exception that explains this if I am trying to create UIElements on a background thread by mistake).

Wrapping my code that adds UIElements to the MainPage with Dispatcher.BeginInvoke solved the problem:

 Dispatcher.BeginInvoke(() =>
 {
      // your code
 });

Answer 5

For me, this was a XAML parsing error. In a data template, I had an extra S between two tags (probably because I pressed S instead of CTRL+S). For example...

<DataTemplate>
   <Border/>s
</DataTemplate>

So, I would suggest you look for poorly formatted XML in the view that causes this exception when displayed.

Answer 6

I also had this error and I found that this problem is related to not have added all requiered assemblies to your project. In my case I was using a UserControl with a depency with the Silverlight Toolkit and I havent added this reference. I just added the reference and everything solved :)