Oh wow Kaye, you’re in a pickle, and one that happened to me as well.
Sewiconz is the villain! I had installed it to see if it was a good option for my students who didn’t have any software to view embroidery designs. What a mess.
When it happened to me it took many, many tries for the Janome team and Wilcom working with me to get the program to work properly again. As Jim said the MBX was the appointed default to display images and Sewiconz overruled that and when you uninstall it permanent changes happened in MBX.
Don't worry, keep at the support people, and they’ll find the solution for your computer. You’ll be changing command lines and they need to determine exactly which.
I wish you good success!