If you are using WorldGuard, make sure you are running the very latest WG build available for your server version. You need WorldGuard 6.2 or higher. You also need MMOItems LegacyWG if you are running WorldGuard 6.2.
Installing MMOItems Premium on Legacy (<1.13)
Since 4.7.6, MMOItems Premium features 1.12 support however 1.14+ remains the plugin native version. You will need to download the 1.12 default config files and install them manually after you have started your server once with the MI build installed.
If you're running WorldGuard on Legacy, you MUST install MMOItems LegacyWG (Download) otherwise MMOItems will spit out an error when loading and it will not enable.
MMOItems WorldDrops allows you to have per-world drop tables for blocks and monstersthis wiki page
MMOItems Mana & Stamina is a simple addon which adds default mana & stamina resources for players. These resources can be consumed to use abilities or weapons. PlaceholderAPI placeholders:
MMOItems Mana & Stamina is NOT compatible with other RPG core plugins which already handle mana and stamina/power like SkillAPI, Heroes or RPGPlayerLeveling. This addon will NOT let you utilize the player level from your RPG plugin when installed.