Hi
Couple of things to check:
1. Can you please check this folder to see if the Configuration was copied over: C:\Users\<UserName>\Documents\ArcGIS\AddIns\ArcGISPro\Configurations
2. Are you able to build an Add-in on this machine? If you create a simple add-in (no need to add any code) using the SDK template, do you see a similar problem where no esriAddinX file is created?
3. Finally, if you can open your csproj file for the configuration that fails to create the ProConfigX file, please check if these lines are there at the bottom:
<UsingTask AssemblyFile="C:\Program Files\ArcGIS\Pro\bin\proapp-sdk-MSBuild.dll" TaskName="proapp_sdk_MSBuild.PackageAddIn" />
<UsingTask AssemblyFile="C:\Program Files\ArcGIS\Pro\bin\proapp-sdk-MSBuild.dll" TaskName="proapp_sdk_MSBuild.CleanAddIn" />
<UsingTask AssemblyFile="C:\Program Files\ArcGIS\Pro\bin\proapp-sdk-MSBuild.dll" TaskName="proapp_sdk_MSBuild.ConvertToRelativePath" />
<Import Project="C:\Program Files\ArcGIS\Pro\bin\Esri.ProApp.SDK.Desktop.targets" Condition="Exists('C:\Program Files\ArcGIS\Pro\bin\Esri.ProApp.SDK.Desktop.targets') AND !Exists('Esri.ArcGISPro.Extensions.targets')" />
Thanks
Uma