Error with nil on_rightclick

[BrunoMine]

I do not understand why this happened.
Minetest 0.5.0
Branch clean_api

8-06-21 00:01:03: [Main]: [advanced_npc] INFO: Successfully registered program '"sunos:interagir_mobilia"'
2018-06-21 00:01:03: [Main]: [advanced_npc] INFO: Successfully registered program '"sunos:walk_to_checkin"'
2018-06-21 00:01:03: [Main]: [advanced_npc] INFO: Successfully registered occupation with name: "sunos_npc_caseiro_lojista"
2018-06-21 00:01:03: [Main]: [advanced_npc] WARNING: Attempt to register an existing texture with filename: "sunos_npc_male.png"
2018-06-21 00:01:03: [Main]: [advanced_npc] WARNING: Attempt to register an existing texture with filename: "sunos_npc_female.png"
2018-06-21 00:01:03: [Main]: [advanced_npc] INFO: Successfully registered occupation with name: "sunos_npc_caseiro"
2018-06-21 00:01:04: ACTION[Main]:         .__               __                   __   
2018-06-21 00:01:04: ACTION[Main]:   _____ |__| ____   _____/  |_  ____   _______/  |_ 
2018-06-21 00:01:04: ACTION[Main]:  /     \|  |/    \_/ __ \   __\/ __ \ /  ___/\   __\
2018-06-21 00:01:04: ACTION[Main]: |  Y Y  \  |   |  \  ___/|  | \  ___/ \___ \  |  |  
2018-06-21 00:01:04: ACTION[Main]: |__|_|  /__|___|  /\___  >__|  \___  >____  > |__|  
2018-06-21 00:01:04: ACTION[Main]:       \/        \/     \/          \/     \/        
2018-06-21 00:01:04: ACTION[Main]: World at [[censored]/minetest 0-5-0/bin/../worlds/soc 01]
2018-06-21 00:01:04: ACTION[Main]: Server for gameid="minetest" listening on 0.0.0.0:30000.
2018-06-21 00:01:07: ACTION[Server]: 888 [127.0.0.1] joins game. 
2018-06-21 00:01:07: ACTION[Server]: 888 joins game. List of players: 888
2018-06-21 00:01:08: [Server]: [advanced_npc] INFO: Corrected position for walking NPC "Trunko"
2018-06-21 00:01:09: [Server]: [advanced_npc] INFO: Corrected position for walking NPC "Trunko"
2018-06-21 00:01:09: ERROR[Main]: ServerError: AsyncErr: ServerThread::run Lua: Runtime error from mod 'sunos' in callback luaentity_Step(): ...npc/executable/instructions/builtin_instructions.lua:675: attempt to call field 'on_rightclick' (a nil value)
2018-06-21 00:01:09: ERROR[Main]: stack traceback:
2018-06-21 00:01:09: ERROR[Main]: 	...npc/executable/instructions/builtin_instructions.lua:675: in function <...npc/executable/instructions/builtin_instructions.lua:663>
2018-06-21 00:01:09: ERROR[Main]: 	(tail call): ?
2018-06-21 00:01:09: ERROR[Main]: 	...Mods/minetest 0-5-0/bin/../mods/advanced_npc/npc.lua:1376: in function 'execute'
2018-06-21 00:01:09: ERROR[Main]: 	...Mods/minetest 0-5-0/bin/../mods/advanced_npc/npc.lua:1408: in function 'execute'
2018-06-21 00:01:09: ERROR[Main]: 	...Mods/minetest 0-5-0/bin/../mods/advanced_npc/npc.lua:1461: in function 'execution_routine'
2018-06-21 00:01:09: ERROR[Main]: 	...Mods/minetest 0-5-0/bin/../mods/advanced_npc/npc.lua:2189: in function <...Mods/minetest 0-5-0/bin/../mods/advanced_npc/npc.lua:2121>
2018-06-21 00:01:09: ERROR[Main]: 	(tail call): ?
2018-06-21 00:01:09: ERROR[Main]: 	...de Mods/minetest 0-5-0/bin/../mods/mobs_redo/api.lua:2579: in function <...de Mods/minetest 0-5-0/bin/../mods/mobs_redo/api.lua:2522>
2018-06-21 00:01:09: ACTION[Server]: 888 leaves game. List of players: 
Loaded texture: [censored]/minetest 0-5-0/textures/base/pack/menu_header.png
Loaded texture: [censored]/minetest 0-5-0/games/minetest_game/menu/header.png

[hkzorman]

@BrunoMine Please update your clean_api branch and let me know if this still happens.