The config.ymtl file of the plugin "Anti World Fly" doesn't let you save changes

Well, so it all started when I made a pvp arena on a new world where you could use /warp pvparena for teleport to it, I didn't wanted donators to fly on that area so I selected it and use /region flag <regionname> blocked-cmds fly, that would desactivate the command fly in that area, but there was an issue that if you had fly enabled on other world ant then tped to that area, you would keep having it enabled, so for that I installed the plugin called "Anti World Fly" and it works correctly, I put the world "pvparena" on the blocked fly list and everything.
The problem is that the plugin shouts messages and titles when you join the world where you blocked fly, and you can actually disable it in the config file, but when I configure that to false, I can't save the changes because it says "error" and an ID, but in general shouts that error when I click on save changes in that file, I dont know why.
I wanted to try with the plugin "NoFlyZone" but its not in this database because its outdated :c
I would really apreciate you to give me ideas to disable fly for that arenapvp.
Thanks for reading and have a nice day