This update overhauls how the MySQL system works. During initial testing, everything seemed okay; however, there might be some bugs. For the new system to function correctly, each table must have its PLAYER_ID row set as the primary key; otherwise, the plugin's queries won't work. I've added a script to upgrade the already existing tables with a primary key, but I'm unsure how it will perform on your end. If it doesn't work, you have two options: either manually make PLAYER_ID the primary key or delete the tables, allowing the plugin to generate new and functioning tables (note that this will reset player data).
GENERAL
Added the "max-pool-size" setting to the MySQL settings (by default, it's set to 5).
BUG FIXES
Fixed: MySQL not closing connections, leading to the "too many connections" error.
Fixed: MySQL not syncing data properly, especially kit selections.
Fixed: MySQL not setting PLAYER_IDs as a primary key.
Fixed: MySQL performing too many queries, leading to lag spikes.