Ref: http://wiki.tk2kpdn.com/build-error-prism5-interactionrequesttrigger-with-vs2015/
gacutil -i "c:\Program Files (x86)\Microsoft SDKs\Expression\Blend\.NETFramework\v4.5\Libraries\System.Windows.Interactivity.dll"
Ref: http://wiki.tk2kpdn.com/build-error-prism5-interactionrequesttrigger-with-vs2015/
gacutil -i "c:\Program Files (x86)\Microsoft SDKs\Expression\Blend\.NETFramework\v4.5\Libraries\System.Windows.Interactivity.dll"