excel add in c#

Hello everyone,

I created an Excel add-in using C# that works without any problems when opened through C#. However, when I try to open the add-in as a file in Excel, the functions no longer work.

I have already checked that the add-in is compatible with the current version of Excel and C#, and have also checked the version numbers to make sure they match. I also tried opening the add-in on another computer with the same version of Excel and C# installed, and the problem still occurred.

Here is more information about the problem:

Problem description: When I open the add-in as a file in Excel, the functions are not available. Instead, error messages appear or nothing happens.
Version numbers: I am using Excel 2016 (version 16.0.4266.1001), C# 6.0, and .NET Framework 4.7.2.
Steps to reproduce: To reproduce the problem, I simply open the Excel file and try to use the add-in.
Error or warning messages: I don't get any error or warning messages, but the functions are simply unavailable.
Debug information: When I open the add-in in debug mode, I don't see any exceptions or stack overflows. The code seems to work fine.
Code Base Information: The add-in is a COM add-in that accesses the Microsoft.Office.Interop.Excel library.
Environment information: The add-in runs on a Windows 10 computer running Office 2016 (version 16.0.4266.1001). No other add-ons or programs are active.

Has anyone encountered this problem?