The VSIX installer sometimes fails to remove the old version of an extension during update; if the same extension is installed twice, VS disables it.
- Close VS and use DuplicateExtensionFinder to remove duplicates.
- Uninstall the extension and restart VS. Repeat until VS does not list the extension any longer. Now install the latest version.
This may have several root causes
- When you see the message
Error: 'Provide value on 'System.Windows.StaticResourceExtension' threw an exception.'
- Multiple versions of some assemblies are used by different extensions. This is a WPF bug that was fixed in .Net 4.7.2 (see https://github.com/Microsoft/dotnet/blob/master/releases/net472/dotnet472-changes.md#wpf). To get rid of this, install .Net 4.7.2 and set
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\AppContext\Switch.System.Windows.Baml2006.AppendLocalAssemblyVersionForSourceUri="true". (https://raw.githubusercontent.com/tom-englert/WpfResourceIssue/master/ActivateNet472WpfFix.reg)
- Some assemblies (usually System.Windows.Interactivity) are loaded twice from different locations. Check the output window to see what locations the assembly is loaded from.
- If it is loaded from the folder of another extension, disable that extension.
- If it is loaded from
C:/Program Files (x86)/Microsoft Visual Studio/2017/<edition>/Common7/IDE/PrivateAssemblies, you can delete it from there. - If it is loaded from the GAC, use gacutil.exe to remove it from there.