I can't get an update to work from vanilla 1.14 to spigot 1.14. The world size is 26GB.

I've tried with and without the forceUpgrade flag and loaded a complete backup between each test. Each time I've tried the preparing spawn area gets stuck at 100% and the CPU usage drops from maximizing all cores to 10% and then stays there. 

No plugins are present for testing purposes. 

The server is frozen and won't accept logins or commands in console. When I kill and start it back up, it still gets stuck. 

Not sure if this is related, but it peaks at 2170MB of ram and flattens out.

I tried to load the 1.14 vanilla world in vanilla 1.14 pre5 and then with spigot 1.14 as well and that got stuck too.

Starting up a 1.14 vanilla server and having a new world only 10MB in size, switching the 1.14 spigot successfully works. It seems as if this is some sort of problem with the size of the world I'm trying to update.