I don't know what happened but since today my Drones refuse to deploy and work. Maybe i did let them work too hard the last days … anyway. There was an update to one Mod i'm using today which was 'Fluid must flow'. Turning off this one doesn't fix the problem. Starting a new game doesn't fix the problem. The Drones just don't leave to work, they just stay in my char's inventory.
I do not have an personal Hanger in my actual game. And like said, even in a new game they just refuse to work. Tried to use 'ALT-R' to switch anyway, but no effect.
Help wanted - i love those little guys doing the work for me and squeeking around all the time :)

Well … i'm confused. I just tried around to get the Drones working again and just completely removed two other mods, which where updated, but NOT active in the played game. Those where Yuoki's Industries and Engines. After that, the Drones worked again. I re-installed Yuokis after that and set it to inactive again - so everything like before - and the Drones still keep working.
So everything fine, besides me totally confused.

Me again. After installing another mod 'Autosort', the drones again refused to deploy. Deactivating and reactivating of this mod, or of 'construction Drones' didn't help. Finally i completely removed 'construction drones' from my game, saved, re-installed it, researched the technology again, build some new drones and now they are finally working again.
Something seems to be happening when mods are installed or updated. Maybe you could look into that at a time? I would be happy to provide you with any further information you need and i'm able to give.

Can you provide a save game with them broken?

Hello! I seem to be having a very similar issue. After updating the mod "Auto Deconstruct" and downloading a new mod "Infinizoom" the drones will never deploy and do work. After uninstalling "infinizoom" they still wont come out and play. However, starting a new game, the drones deploy just fine. Going back to my main save afterwards, they still don't deploy. The drones were working perfectly fine for many many hours, until i downloaded and updated mods.

Here is a link to download my save with the drones in the broken state:
https://drive.google.com/open?id=1qiXjPI4AN9oygCZf0XsAceq6khEVvJGb

edit: I got the drones to deploy again by uninstalling the mod, loading and then saving my world (clearing the mod from my world), reinstall the drone mod, and re-researching the drone tech.