I think 1.14.3pre4 will come out sometime this week. If I am reading the description here correctly it has been delayed and should have released 2 days ago. It's possible they delayed either because this bug hasn't been fixed yet, or they are planning on releasing 1.14.3 and wanted to fix some more stuff.
I can confirm this has something to do with the generation of end ships. Tested it out and the game only crashes when it has to generate end ships and worked fine with an end city without one. Maybe it has something to do with the item frame containing the elytra?
Gavin L Moreland
I think 1.14.3pre4 will come out sometime this week. If I am reading the description here correctly it has been delayed and should have released 2 days ago. It's possible they delayed either because this bug hasn't been fixed yet, or they are planning on releasing 1.14.3 and wanted to fix some more stuff.