Does the STAR in question include “EXPECT RADAR vectors to…”?
I’ve seen this on one of my flights. I departed (it let me depart) with the discontinuity and when close to the last fix in the STAR, I hit direct to the first fix in the approach. This worked. It was the IRONS 7 arrival into KDCA (I know, probably not an airport you’d expect to see an A310 but anyway).