If your server is crashing with the error java.lang.IllegalArgumentException: ChunkNibbleArrays should be 2048 bytes not: 0, it means that your world is corrupt.
This error usually occurs when switching between server version (such as between 1.12.2 and 1.13.2) or server type (such as between Forge and Spigot/Vanilla). It is especially likely when downgrading to a lower version, or switching between vastly different versions
Luckily, we have a guide providing more information and steps on how to fix corrupted world chunks. So you can either fix the corrupted chunks manually, or you can generate an entirely new world.