Factorio Forums

Ok, this one is going to be a bit vague, but I feel obliged to at least mention encountering it.

Sometimes (but not always) when placing a blueprint with a personal roboport active, the construction robots will fly out and build the stuff, and then return, filling up in your toolbar in the slot where the blueprint was, with the blueprint ending up in your inventory.

I was unable to figure out what exactly caused this, when I tried to reproduce this the robots went to my inventory each time. Perhaps it's something with the timing of robots flying out, returning, while you press Q to return the blueprint to the toolbar? I was unable to determine this.

I did not have any empty slots left on my toolbar.

I tried to reproduce it without a success, I'm moving it to pending then, If you come up with reproducible solution, I might try to do something about it.

I'll keep an eye out. I have it sometimes, but I never realize I had until I find construction bots on the toolbar instead of the blueprint

I finally discovered what was causing this.

If you grab a blank blueprint out of your toolbelt, and then drag to create a non-blank blueprint, the toolbelt "forgets" that the blueprint was in it. Then when you order construction of your non-blank blueprint (without ever putting it back in the toolbelt), the construction robots will see an empty space on your toolbelt and go there when they come back.

This is not really a bug. The blueprint changes so the toolbelt acts accordingly. It can sometimes be a minor annoyance, however.