Information

Environment information
Plugin + server version info:
[01:00:18] [Server thread/INFO] [Console/]: ##### Start Minepacks version info #####
[01:00:18] [Server thread/INFO] [Console/]: Minepacks: 2.4.5.1-Release
[01:00:18] [Server thread/INFO] [Console/]: Server: arclight-1.16.5-1.0.24-SNAPSHOT-156b78b4 (MC: 1.16.5)
[01:00:18] [Server thread/INFO] [Console/]: Java: 11.0.13
[01:00:18] [Server thread/INFO] [Console/]: ##### End Minepacks version info #####

Online mode: Yes
BungeeCord: No

Server/crash log
https://gist.github.com/goreziller/447cf5cb99a78d78f667470a0cc1c17d

Plugin config (optional)
https://gist.github.com/goreziller/d79347b3156c057aa6438da48d2d6361

Details

Description
I think because the server hung for a long time, the connection was broken and then when the server caught itself, the plugin could not establish a new connection because it still existed.

Yes, this was most likely caused by the server hanging. Though I would have expected that it would fix itself, shortly after the server resumes to work normally.