Welcome to the forum, vgmiller!
I don't know about remembering something. There are so many digital cutters these days, I can't keep up. I don't own or use any of them. There is a current issue in another topic about DXF and Silhouette. But about SVG and Cricut.... Well, there might be other messages about Cricuts, and you could certainly search.
Have you been able to use SVG files from Inkscape in the past? Or is this the first time you're tried?
Repeating what Moini asked, is there an error message?
Isn't MTC the native Cricut software? I guess it's no surprise that its own software works.
Does Cricut accept any other formats?
If you'd like to share the SVG file with us, I guess it's possible you don't have everything converted to paths. Or if you know what that means, you could double-check yourself.
I guess it might be interesting the compare an SVG from MTC with an SVG from Inkscape. You're welcome to share those with us, if you like, although I don't have any idea whether I might find anything helpful.