Importing X7 Files

I upgraded to X7 and am using it on Windows 10.  I don't have any issues importing any of my old X3 files, but when I try to import an X7 file it takes up to 15 minutes for the file to load.  Once it loads I can resave it in X3 format and it imports fine, but it is kind of a pain.  If I do resave it as an X3 file under the same file name it creates 48 backups of the original X7 file.  I assume that is why the files take so long to load but I have no idea why that's happening.  Can anyone help me out with this?