I got a crash/non recoverable error when i tried to upgrade the furnace stack from yellow to red belts, reloaded, did so again without problem, went to upgrade balancer from yellow to red and got the same error again.

don’t know if we can share images here, so my poor attempt at writing down the error
Error while running event blueprint-shotgun::on_script_trigger_effect(ID 175)
LuaEntity doesn't contain key neighbors.
stack traceback:
[C]: in function'index'
__blueprint-shotgun/scripts/build/upgrades.lua:33: in function 'process'
blueprint-shotgun/control.lua:223: in function
<blueprint-shotgun/control.lua:143>

for some reason it worked well for most of today, only after couple hours of game this started to happen
i have no idea what this is, hope it helps with solving the bug/crash/non recoverable error, thanks
without this tool i feel like i went back to stone age, please help

seems that two _ _ one after another cause the line to be bolded, please take that in mind whenever looking at the log. i also have a screenshot of it i can share if needed

Sorry about that, fixed in 0.3.1
The issue was with upgrading underground belts, the API changed around those recently and I wasn't aware until after releasing the update.
The documentation had a bug when I was updating mods, and I wasn't able to tell which code warnings were real or fake, so I glossed over this one.

Also, don't worry about the underscores, we're used to seeing bold instead of them.
By the way, you can actually select the text in the error and copy it if/when you ever get a mod error in the future, instead of having to type it out yourself.
I appreciate you doing that nonetheless!

many thanks for quick fix, i dont think i can go back to playing pre this mod, you are a godsend, may your factory grow far and wide and your SPM reach the heaven