Hi,
I developed an Add-In toolbar for ArcGIS 10 using .NET SDK and MS VS Express 2008 in 2012. Now I have migrated to ArcGIS 10.5 and MS Visual Studio Community 2015. When I open my old toolbar in MS VS community 2015, it gives errors, "references not defined"(I have attached two images of the errors). Even after I define the reference paths (C:\Program Files (x86)\ArcGIS\DeveloperKit10.5\DotNet\Toolboxes\ and C:\Program Files (x86)\ArcGIS\DeveloperKit10.5\DotNet\Toolboxes\) only some reference locations were updated. Others are still the same ("The system cannot find the reference specified"). Can anyone please help me on this? Thanks