Error with projector and merge block

Today I came across a bug in the game while trying to build a drone factory with automated launch system.

My projector is located on a rotor (because it is a small grid drone) and the rotor is mounted on the launch piston. The drone has a pair of merge blocks that form the connection point to the projector. That way I tried to automatically disconnect the drone from the projector using an action relay that deactivates the merge block and sets the drone free. Everything pretty much works fine but when the merge block deactivates there is a message coming up saying "Can not find blueprint". This error message can not be confirmed or dismissed, Esc is not working and the game can only be closed with Alt-F4.

One of the 2 merge blocks stays on the projector after launch. I was hoping that the projector would be able to project the blueprint after the launch so the factory immediately starts assembling the next drone.

I will try a different approach the next time and maybe locate one of the merge blocks on the same grid as the projector and only print the other merge block on the drone. Or maybe connectors will do the job.

Nevertheless I still think a message that cannot be confirmed and basically crashes the game is a bug the dev team might be interested to know about and maybe it can be fixed. I will attach a screenshot of the message but it is in german.