Why am I getting 'Assembly '*.dll' must be strong signed in order to be marked as a prerequisite.'?

Question

I\'m trying to compile my excel addin using C# 4.0, and started to get this problem when building my project in Visual Studio. It\'s important to tell you that I haven\'t had th

Answer 1

I encountered this problem after migrating an Excel Addin from packages.config to PackageReference. Seems to be related to this issue.

The following works as a crude workaround if you're not using ClickOnce (it will omit all the dependency information from the .manifest file):

1. Unload project, edit .csproj

2. Find the section looking like this:

3. Edit a renamed copy of the referenced .targets file (in my case, the file resolved to C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\OfficeTools\Microsoft.VisualStudio.Tools.Office.targets and I made a copy Microsoft.VisualStudio.Tools.Office_FIX.targets in the same folder - didn't check if it works from a different folder).

4. Find the GenerateApplicationManifest element and change its attribute Dependencies="@(DependenciesForGam)" to Dependencies="".

5. Change the section found in 2. to reference your edited .targets file instead.

This will have to be repeated whenever the version of the .targets file shipped with VS is updated (or you won't get the updates), but I'm hoping it will be fixed soon...