no mods, when changing a existing belt direction, for each belt changed get error message :
5772 on_pre_player_minied_item {entity = {_self = "userdata" } , name = 11, player_index = 1, tick 5772
also
When reducing an player stored item causing size reduction get errors also.
so far does not cause fatal error just annoying.
This a great mod, hope you still can update it.

Thank you for reporting. I've added this to my list. 👍

I get the rotating idea for the first issue, but I'm not sure about the second one about player storage? 😕

i often get this exact error message when dragging red belt across obstacles, generating undergrounds. not all the time, but often enough that i recognise it.

i've never seen this error dragging to generate undergrounds with yellow belt; i don't have blue belts.