After reloading my server, when a player leave there is an error and players can't reconnect/ping.
Error Log: https://pastebin.com/uP69yr8a
Dump: https://pastebin.com/jh8B9eWs

you cant reload protocollib. you should reload invidivual plugins or just restart your server like any sane admin.

I am creating my own plugins and restarting my server everytime is slowing my tests.
Your advice yould be to use something like plugman and reload only my plugin?

After researching a little more i found a fix using ProtocolLib Reload Fixer
https://www.spigotmc.org/resources/protocollib-reload-fixer.66860/

Maybe it could be added officially (｡◕‿◕｡)
Thanks for helping

No.
The reload command is bad and shouldnt be used.
For dev purposes, you should look into hotswapping but ye, alternatively plugman is kinda acceptable.

I'm intrigued that someone made that reload fixer plugin. But yeah reloading is not currently supported and will never be recommended