I had Even Distribution, RPG Items and Transport Drones active in the same save file. Then I removed Transport Drones, now I get the following error on load:

The mod Even Distribution (0.3.16) caused an unrecoverable error.

Error while running event even-distribution::on_configuration_changed

The mod RPG Items (0.18.8) caused an unrecoverable error.

Error while running event rpg_items::on_technology_effects_reset (ID 99)
Unknown category name: transport-drone
stack traceback:
    __rpg_items__/rpg_framework.lua:781: in function 'add_modifier'
    __rpg_items__/control.lua:329: in function <__rpg_items__/control.lua:319>
stack traceback:
    [C]: in function 'get_ammo_damage_modifier'
    __rpg_items__/rpg_framework.lua:781: in function 'add_modifier'
    __rpg_items__/control.lua:329: in function <__rpg_items__/control.lua:319>
stack traceback:
    __even-distribution__/scripts/setup.lua:53: in function 'applyEarlyAutotrash'
    __even-distribution__/scripts/setup.lua:20: in function 'func'
    __even-distribution__/framework.lua:99: in function 'handleEvent'
    __even-distribution__/framework.lua:108: in function <__even-distribution__/framework.lua:108>
stack traceback:
    [C]: in function 'reset_technology_effects'
    __even-distribution__/scripts/setup.lua:53: in function 'applyEarlyAutotrash'
    __even-distribution__/scripts/setup.lua:20: in function 'func'
    __even-distribution__/framework.lua:99: in function 'handleEvent'
    __even-distribution__/framework.lua:108: in function <__even-distribution__/framework.lua:108>

fixed (0.18)
you should get a message instead now..

Thanks a lot :)