How do I modify the setup configuration so the Excel file can find the required files installed in the installation folder, even when the Excel file is saved to folders on the network servers?

Question

I am developing an Excel VSTO Workbook (C#) application for work using Visual Studio 2022. This is NOT an Add-In project. This application must run on either Windows 10 or Windows 11.

 

This application includes a custom Ribbon Tab that runs various calculations projects and Forms projects included within the Visual Studio Solution when objects on the Ribbon Tab are clicked. This application will need to be installed on multiple workstations and the Excel file needs to be saved on the network servers in each project folder.

 

In Debug mode, the application works perfectly. Following the instructions included at this website https://learn.microsoft.com/en-us/visualstudio/vsto/deploying-a-vsto-solution-by-using-windows-installer?view=vs-2022, I have successfully created a deployment that can be installed on multiple workstations. The application runs perfectly as long as the Excel file is opened from the installation folder.

 

Once the Excel file is saved to another folder and opened from that folder, the Excel file throws exceptions when opening with messages indicating it cannot find the associated “vsto” file for this application. This “vsto” file is located in the installation folder.

 

I created a simple test project to display a message when the Excel file opens to see if a simple project would install correctly and got the exact same error messages.

I suspect this may be a Registry issue, but I have no knowledge about how to modify the Registry correctly if this is the problem.