Why does my Minecraft server fail when I join it?

Hi, I have a 1.12.2 Minecraft server that runs with Magma. Magma is a server software with which I can run Forge Mods and Plugins on one, something like Sponge.

The server ran stably until the server's memory was full. I downloaded a couple of backups and then deleted them. But when I wanted to start the server again, it went out when I wanted to enter it. I did not receive a crash report either. I hope you can help me ^^.

Ps: I put the last log in for you on Dropbox because the log is too big for Patebin:

https://www.dropbox.com/...t.log?dl=0

If you read where you are entering the server at 9:31:21, the server reports an error. I don't really know my way around, but would interpret it as a chunk error. So something was not saved correctly when it crashed, where it now has a loading error. Do you have a world backup before the crash that you can restore? Worth a try. But it's just a good idea. Otherwise, wait and see if someone knows their way around who definitely has a solution…

Yes but then I delete a couple of hours of work.

Well, otherwise you read into Worldfixer and try to fix the world. If you google the "Forge Chunk I / O Executor Thread-2 / ERROR" error, you will find several entries on corrupt world data, which confirms my assumption… There are also terms like Worldfix etc… If necessary, there's a possibility to add the defective data replace… Alternatively, just play back the backup. In any case, save the current world again before you try something. Maybe choose shorter backups in future…

Could it work that I take a backup where the problem was already there? Sorry for the stupid question, but I really don't feel like earning everything again.

A faulty backup will also crash, you can also try a backup to fix the error. But to play you need a version that was still bug-free or is bug-free again. Be glad you have backups. Imagine if you had no backup and everything would be gone…