My standalone C# app checks out files from, rebuilds them, and checks them back in. Occasionally, Microsoft Excel opens on its own. I close it only for it to open again. How is Excel connected to the SolidWorks API? Is there a way to prevent Excel from opening?
You said "My standalone C# app..." Does that mean you wrote it, or you just have it? Do you have the source code to debug it? You need to figure out which SW files are causing Excel to open during a rebuild.
My first guess would be an Excel-based BOM (which have been legacy functionality since about 2004 and probably should not be used). Excel is used for a couple more things, but I think the BOM would need to hit up Excel during a rebuild.