Installing Office Customization

Question

Name: From: file:///D:/Samples/TestUpdatedVersion/bin/Debug/TestUpdatedVersion.vsto

The customization cannot be installed because another version is currently insta

Answer 1

We have a number of products using VSTO on Office 2007, Office 2010 and Office 2013 on various Windows versions. The Deployment.AddInAlreadyInstalledException occurs often during deployments. The problem seems to occur especially on PCs with many install/deinstall cycles (such as of IT personnel itself). Often leaving me with gray or no hairs, since a re-install is not always easily possible and the source is unclear.

As there is not a silver bullet to fix any source of the problem (other than reinstalling Windows), I have gathered experiences in a blog post on steps to resolve AddInAlreadyInstalledException

Maybe this helps other users of VSTO and Microsoft Visual Studio.