I have very few Mods installed, but yes I have "Bottleneck"
I think that is probably the explanation, except I can't even find the info from the ' Bottlenesk" web site

Hi,
I am looking for a comprehensive guide to the various symbols that can show up on your buildings/equipment.
For instance I have factory buildings that seems to be working but show a yellow II symbol on them.
Also I have see a red exclamation point. I would just like a guide to understanding the ...