My server keeps crashing. It will not even load the world. This is my first 1.15 server, I have successfully set up 1.7 and 1.12 servers without much trouble. If you need more information, ask. I have likely missed including something important.
Main error message is: Exception in server tick loop, and Use JsonReader.setLenient(true) to accept malformed JSON
I have attached the most recent crash report and server log here.