Any item placed into the equipment grid of Carl (any version of Carl) or base game spidertrons causes an error. I tried replicating the error Eerhard had, the armor does not have this error.

Mods installed and enabled:
Base Mod
Spidertron Enhancements
Start With Spidertron

error
The mod Start With Spidertron (1.2.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event ProtoSpidertron::on_player_placed_equipment (ID 40)
ProtoSpidertron/control.lua:318: attempt to index global 'inner_event' (a nil value)
stack traceback:
ProtoSpidertron/control.lua:318: in function 'reevaluate'
ProtoSpidertron/control.lua:369: in function <ProtoSpidertron/control.lua:369>

I've never been happy with the speed scaling (which is what that error is related to) so I have plans to remove it and refactor for later addition in a future release. The next update will have it removed and fix the issue you're encountering; I expect it to be available early this upcoming week.

Thank you for your comitment to Carl, I love him so much! This is such a loveable little fella. :)

Thanks, I appreciate the kind words. The Spidertron Engineer mod really inspired me, but I wanted something more flexible, and then it has just kinda grown from there. I haven't gotten far with playtesting yet so feedback is welcome.