Error HRESULT E_FAIL has been returned from a call

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's a very generic error. The VS debugger doesn't point to the exact location of the error when debugging.

Answer 1

I fixed this error by deleting the XAML file and add a new one from add new item. Then I pasted the XAML codes that was there in the old file.

Answer 2

I had this problem while I was encoding Live video and audio (using Microsoft Expression) and the next piece of code throws the exception randomly:

// Set bitrate
liveJob.OutputFormat.VideoProfile.Bitrate = new ConstantBitrate(2500);

// Set Video size
liveJob.OutputFormat.VideoProfile.Size = new Size(320,240); 

until i've figured out that the second line throws the exception while the first one is still running in another thread !

and of course, it was my fault - i've called the method in code, and it was also been called by Click event...

Answer 3

This is kind of an old question, but I figured I'd give my answer since I found this thread by Googling for the exact same problem.

In my case, I'd copied some sample XAML from the web to get started with Silverlight Toolkit 4. That sample XAML contained a simple button with a click event handler that didn't relate to any handler that actually existed in my code behind. I didn't notice this simple problem at first, because the compiler didn't give me an error message, I just saw the "Error HRESULT E_FAIL has been returned from a call to a COM component" message above at runtime. It was only when I isolated my sample XAML by copying it into a brand new Silverlight application without any other content that the real underlying problem was revealed at compile-time.

So, if you've got the same error message at runtime, my advice is to check your XAML carefully for any errors that you had expected should have been picked up at compile time, but which for some reason ended up as the runtime error noted above. In order to debug, you can do what I did and isolate the code that's causing the error in a standalone Silverlight app with no other content, and see if like me you get a more helpful error message to guide you.

HTH.

Answer 4

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 5

This error seems to be a 'catch-all' for errors that otherwise are not given a specific definition or tracing, especially those having to do with relatively external Xaml code.

In my particular case, there seemed to be an issue with the namespaces. My UserControl is in its own namespace (creatively named "UserControls"). My Pages are in their own namespace ("Pages"). I wanted to reference an enum definition in the Pages namespace from within my UserControl, so I simply added a using statement: using MySolution.Pages;. Trivial enough, and I didn't want to believe that this was the problem. But when I removed that using statement and simply created the enum in my UserControls namespace, voila, no more HRESULT error and also, as an added bonus, my dependency properties defined in the UserControl, which otherwise were mysteriously not showing up in the Xaml intellisense, suddenly were there and ready to use.

I suspect that underlying cause for this in my case was some sort of circular reference issue. And since there was no more specific error available to relate that information to me, it simply got shuffled into this HRESULT E_FAIL Com error.

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 :)