Server.jar update: stuck at "Preparing spawn area: 0%"

I recently setup a LAN vanilla mc server v1.14.1. All went fine.

Then I wanted to upgrade to 1.14.2. Replaced the server.jar, started the server, but now it stays stuck at Preparing spawn area: 0%.

When downgrading to v1.14.1 everything works, again.

Please see the attached map file, thank you.

 

Steps to reproduce:

start with 1.14.2 server.jar

• java -Xms1G -Xmx4G -jar minecraft_server.1.14.2.jar nogui
• -> stuck at "Preparing spawn area: 0%"

start with 1.14.1 server.jar

• java -Xms1G -Xmx4G -jar minecraft_server.1.14.1.jar nogui
• server starts up fine