There were three issues that I fixed:

1. Way https://www.openstreetmap.org/way/1304671097 met https://www.openstreetmap.org/way/1304719438 one node away from the end.  This is the mistake that broke rendering on the OSM website.

2. The way https://www.openstreetmap.org/way/807023986 intersected itself twice.  The renderer for the OSM website can handle this, but others can't.

3. The way https://www.openstreetmap.org/way/1293734411 didn't have a role.  This keeps this specific way from rendering, but won't break the rest of the relation.

JOSM has much better QA tools for spotting relation errors than iD does, though it's also considerably harder to use.