File association changes won't stick

I have a bunch of .svg files that I want to associate with the software for my Silhouette digital cutting machine. I do the whole procedure - go to Get Info, then change Open with: to Silhouette instead of Safari, then choose Always Open With, then click Add, then click Change All, then click continue. When I click continue, the Open with flips back to Safari. I can't believe there's no way to change all files to associate with another app. Anyone have any ideas on how to fix this?