Solidify Modifer Apply Fails

The solidify modifier on the arrowhead in this model

Alternative download:

will not apply. Why?

This file’s “Arrow High Rez” collection is for export to Collada followed by its upload to Second Life. An evaluation for any other possible issues that could make that upload to Second Life fail would be appreciated.

It applied without problems when I tried it with your file, (Blender version 2.93)