The Belt Visualizer mod (2.0.2) caused an unavoidable error. Please report this error to the mod's author.
Error while running event belt-visualizer::on_tick (ID O) real number expected got table.
stack traceback:
[C]: in function 'draw_line'
＿belt-visualizer＿/scripts/rendering.lua:32: in function 'dash'
＿belt-visualizer＿/scripts/highlight.lua:221: in function '?'
belt-visualizer＿/control.lua:338: in function
＿belt-visualizer__/control.lua:306>

I got this exact same error today when placing yellow "corner" belts to connect red & yellow underground ghost belts together. This hasn't happened before with many hours of use and I had a recent auto-save so it didn't worry me much, but I figured I'd report it at least. Hope this helps.

I was able to replicate this error - it happens consistently if I place a yellow underground belt, queue it to be upgraded, then queue a red underground belt to be placed where it'll connect, but one tile beyond the max range of a yellow underground belt. Then, clicking the belt visualizer hotkey on the red underground belt ghost causes it to crash every time.

Got the same error, but for me it happened right after some belts were destroyed, and I hovered over the line that was partially destroyed.

The mod Belt Visualizer (2.0.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event belt-visualizer::on_tick (ID 0)
real number expected got table.
stack traceback:
[C]: in function 'draw_line'
belt-visualizer/scripts/rendering.lua:32: in function 'dash'
belt-visualizer/scripts/highlight.lua:221: in function '?'
belt-visualizer/control.lua:338: in function <belt-visualizer/control.lua:306>