Hello robot256,

I maintain Circuit-Controlled Routers, and this mod has a conflict with it, which I believe is a bug in Shipping Containers. This was reported by a user at https://mods.factorio.com/mod/router/discussion/67d1143c4688f651992c7652 with an error shown at https://imgur.com/K0HRDUG. The crash seems to be caused by makeGateBelt trying to set belt_item.minable.result (on gate_belts.lua line 64) without checking that belt_item.minable ~= nil. Because Routers contain modded belts that are not minable (they are sub-entities of the router and are removed when the router is removed), makeGateBelt crashes when copying those belts' prototypes.

Please note that these internal belts also don't have any recipe or associated item, so there might cause further issues in makeGateBelt: you'd probably want to either not copy non-minable belts, or not make items and recipes for the copies if the original belts don't have items.

Shipping Containers probably can't be passed through Routers anyway, but it would be nice if the mods would load together.

Thank you for reporting this! Sorry for the delayed response. I should have mentioned that this bug could be bypassed by disabling the "make modded belts into gate belts" setting. Now Shipping Containers will not attempt to make gate belts out of non-minable or hidden belts.

Thanks for fixing it! No worry about the delay. I've got some long-standing items on my mod backlog too.