set property 'system.windows.resourcedictionary.deferrablecontent' threw an exception - visual-studio

Question

I'm running Visual Studio 2012, when I add a new File/Reference to a project the message box appears showing the error message
set property 'system.windows.resourcedictionary.deferrablecontent' threw an exception
I read an MSDN article suggesting to run the command devenv /resetuserdata on visual studio command prompt to resolve this problem, tried it but didn't work for me. In fact the command prompt shows the Unknown Error message.

Answer 1

Some addins cause this issue for me so have had to workaround it whenever it occurs:
In Vis studio -
Tools > Options > Environment > Add-in Security, uncheck 'Allow Add-in components to load', OK
Restart vis studio
The error shouldn't occur anymore, so go back to
Tools > Options > Environment > Add-in Security and re-check Allow Add-in components to load, OK
To be specific, I get this error when trying to add files to projects and manage Nuget Packages.
Update
I now make a point of opening
'Tools > Nuget package manager > Manage nuget packages for solution'
whenever I open up a new instance of Vis studio, before loading a solution, just to make sure the window loads properly
That way I know I won't get this issue.

Answer 2

In my case it was a style with the same key defined twice in a ResourceDictionary (WPF)

Answer 3

I have Windows azure tools for Microsoft VisulStudio 2013- v2.2 and Windows azure tools for Microsoft lightswitch VisulStudio 2013- v2.2.
I uninstall only Windows azure tools for microsoft lightswitch vs 2013 .
It's working fine...

Answer 4

I fixed it. The resolution was to remove the Windows Azure Tools for Visual Studio 2012 which I was not actually using, and the error went straight away.

Answer 5

In my case it was to first launch Visual Studio in safe mode. You can create a shortcut for visual studio with a target like this:
'"F:\Program Files\Visual Studio\VS2013\Common7\IDE\devenv.exe" -safemode'
Once launched in safe mode, you can remove the problematic extension via the Addin Manager. However, this wont work for some extensions, as the uninstall option might be disabled for certain extensions when running in safe mode, particularly if you have already uninstalled another extension in the same session.
In My case the problem was caused by Paradox Game engine, in which I had uninstalled it via 'Programs and Features' - which in return did not remove the extension which was originally installed via Nuget package. Uninstalling Paradox via "Programs And Features" left the extension itself still registered in Visual Studio, presumably causing a hidden NullReferenceException.
This issue can be caused by any extension that may have an error in it, or by extensions that were not properly uninstalled.
Also, see this article...

Answer 6

The mentioned issue can be resolved by simply restart the Visual Studio. :P

Answer 7

Also seem to be able to get around this by closing the project and vis studio instance, re-opening, then when the start page/open project screen appears selecting Tools > Extensions and Updates..., then pressing Close
Now open the project and the error doesn't get thrown when trying add files or manage nuget packages, weird.
Just annoying you have to remember to open Extensions and Updates each time...

Answer 8

Other wise make sure given Resourcedictionary.xaml path is correct or not

Answer 9

I had to remove Xamarin from Add/Remove Programs in Control panel and restart Visual studio to fix this.

Answer 10

I had this problem with My Devexpress Project in VS 2015
What finally worked for me was.
Close my solution,
Close Visual Studio,
Open Visual Studio,
Create a New dummy project,
Add a form to it,
Close and save the new project,
Reopen original project and all was ok.

Answer 11

for everyone else who are working in silverlight sdk environment with windows phone8 sdk.
The versions of sliverlight which are compatible with visual studio versions -
vs2012- sliverlight sdk 4
vs2013- silverlight sdk 5
I was integrating in vs2013 and as soon as I updated it with silverlight sdk 5, The errors went away.

Answer 12

In my case it was the Line Endings: you can have different formatting and by copy pasting some code one file got a different Line Ending. It was enough to File > Save As and then click the little arrow next to the save button.
Then click on save with encoding and choose the one you are using in all other files.
See Andrew Truckle's answer.
I hope this helps