Finally, after what seemed like an eternity, Alex discovered the solution. A small, yet crucial, update to the DLL's manifest file would allow it to work seamlessly with Excel 2019. With the fix in hand, he quickly rebuilt the DLL and deployed it to the team's test servers.
The problem began when users started reporting that their add-ins, which relied on the utilities DLL, were malfunctioning or failing to load altogether. Alex and his team soon discovered that the DLL was not compatible with the new version of Excel. microsoft.office.tools.excel.v4.0.utilities.dll
Here's a story about the mysterious DLL: Finally, after what seemed like an eternity, Alex