Hey, a fellow Flexi User! I've used FlexiExpert since it was CASMate. I also do my artwork in Flexi, then export as .eps to VCarvePro. On occasion, I have the same problem you're having. It's usually been 2 vectors stacked on top of each other. Once in a while, for some reason, the export to .eps then import to VCP creates an open vector. So, check for open or stacked vectors on the inside parts.
Aspire 9.5 - FlexiEXPERT 11 - Vytek Rebel 4' x 8' - 5HP Perske Spindle