Hello, Many of the STARS in the U.K. end in a holding pattern to await vectors from ATC to the approach. At the end of the STAR LNAV disengaged due to route discontinuity. I knew this would happen and switched to heading hold and vectored myself onto the approach, however when I tried to re-engage LNAV it does not engage, heading hold stayed on and the FMC said "Route Discontinuity" in the scratchpad. I had set my heading to pass directly over the first way point on the approach, that way point was highlighted in magenta in the "Route" page, and the angle between my heading and the heading after the way point was very small. Any ideas? Thanks in advance!

Maybe go into the FMS and make sure the legs connect? If there's four squares you need to connect the route.

There shall be no disco at the beginning of the legs page. If it doesn't work, fly a heading directly towards the waypoint you want to go to and reselect the waypoint to the top of the legs page (downselect by pressing appropriate LSK and reinsert into first position, then execute).