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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(54.400000000000006, 27%, 15%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESR%3C/text%3E%3C/svg%3E)
I was having my outlook desktop add-in in .NET framework version 4.8. Recently, I have migrated it to 6.0.
It's having 4 projects :
Project 1 (WPF Class library)
Project 2 (WPF Class library)
Project 3 (C++ Shim Project)
Project 4 (WPF Application)
Everything building successfully. Add-in is getting registered on registry with success. Add-in is not getting disabled.
But still I am not able to see my add-in on outlook ribbon.
Don't know what is exactly happening.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(48, 63%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EEA%3C/text%3E%3C/svg%3E)
VSTO like any other frameworks for developing COM add-ins doesn't support .Net core (or custom shimmed projects).
.Net standard can't be used for developing COM add-ins, you need to use any .Net framework versions, but not Core (.net standard). If you try to create a new VSTO add-in for Outlook you will not find any .Net Standard (Core) versions in the list of available target .net versions.
Thanks for clearing. All these I have to do because I have one external class library (5th project) which I have to use in Project 2 (WPF Class library). Project 5 is developed in .net6.0 and Project 2 is developed in .NET Framework v4.8. Can I use Project 5 in Project 2 ?
Thanks for clearing. All these I have to do because I have one external class library (5th project) which I have to use in Project 2 (WPF Class library). Project 5 is developed in .net6.0 and Project 2 is developed in .NET Framework v4.8. Can I use Project 5 in Project 2 ?