Failed to load addin message
Error Message: <UnknownError> Error Number: 80131515
It may be necessary to enable loadFromRemoteSoruces in the development environment to run the addin.
In your visual studio directory add a line <loadFromRemoteSources enabled="true"> in the devenv.exe.config
In this file in the (Correct visual studio folder):
C:\Program Files\Microsoft Visual Studio (#)\Common7\IDE\devenv.exe.config
Or
C:\Program Files (x86)\Microsoft Visual Studio (#)\Common7\IDE\devenv.exe.config
Add loadFromRemoteSources element with "true" value, like below,
<configuration>
<runtime>
<loadFromRemoteSources enabled="true"/>
...
</runtime>
</configuration>