ArcGIS 10.4. Problem with add-ins backward compatibility

[AntonPerlov1]

Hello everyone. I have a problem with backward compatibility with ArcGis Desktop 10.4 and .NET add-ins built for earlier versions of ArcGIS Desktop.

I have a .NET add-in built for ArcGIS Desktop 10.3.1. When I try to install add-in by double-clicking add-in file, i get the message "Installation succeeded", but add-in does not appear in  add-in manager dialog. In fact, add-in succesfully installs only in a second attempt. If i try to install add-in using Customise -> Add from file, i get error message:

"No GUI components found in this Add-In.

Add-In version does not match."

When I try to install add-in built for ArcGIS 10.4 on ArcGIS 10.4.1 I get the same problem.

Al i want is to build add-in for ArcGIS 10.3.1 which would be normally installed on 10.4, 10.4.1 and later versions of ArcGIS desktop. Can anyone help me to solve this problem?

[EmilyBunse]

I think that's what I'll have to do the same. Since my original post, I've reverted my laptop back to the 10.3.1 Desktop instead of updating my Developer tools to 10.4 (I'm on a time crunch due to a conference). I just have to hope that when I'm done making the Add-In for .NET 3.5, I have similar luck with compiling for .NET 4.5. I already knew I'd need to completely overhaul the Add-In for use in ArcPro, so this is just one more thing.