You have the same problem that the OP in this post had regarding the path to the NI_Excel.lvclass. They ended up reinstalling LabVIEW but I think that is a bit extreme and not needed. You can do as I mentioned above and drop the Excel Get ActiveX Reference into your code and recompile or you can follow Darren's advice for trying to correct the dependency path and "Always Include" the lvclass in the build.
The XLM code below is viewed by right-clicking the project file and editing with a text editor.

Dependency should look like this when added to the project correctly.

aputman