https://github.com/pyanodon/pybugreports/issues/336

changelog.txt

@@ -13,6 +13,7 @@ Date: ???
     - Fixed that dingrit mk2,mk3,mk4 module recipes were not outputting any empty cages
     - Moved all aerial turbine code to pyAE
     - fixed digosaurus being recorded in kill statistics
+    - fixed crash when mixing oculas and factorissimo 2 (https://github.com/pyanodon/pybugreports/issues/336)
 ---------------------------------------------------------------------------------------------------
 Version: 2.1.9
 Date: 2023-9-4

scripts/ocula/ocula.lua

@@ -21,7 +21,12 @@ Oculua.events.on_init = function()
 end
 
 function Oculua.set_target(oculua_data, target)
-	oculua_data.entity.set_command{
+	local entity = oculua_data.entity
+	if entity.surface_index ~= target.surface_index then
+		Oculua.go_home(oculua_data)
+		return
+	end
+	entity.set_command{
 		type = defines.command.go_to_location,
 		destination_entity = target,
 		radius = Oculua.range,
@@ -232,7 +237,12 @@ end
 function Oculua.go_home(oculua_data)
 	local ipod = oculua_data.ipod
 	if not ipod or not ipod.valid then Oculua.wander(oculua_data); return end
-	oculua_data.entity.set_command{
+	local entity = oculua_data.entity
+	if not ipod or not ipod.valid or ipod.surface_index ~= entity.surface_index then
+		Oculua.wander(oculua_data)
+		return
+	end
+	entity.set_command{
 		type = defines.command.go_to_location,
 		destination_entity = ipod,
 		radius = 0.5,