Help, crafters not crafting

My crafters are stuck between idling and gathering ingredients, i have all the materials but they they dont do anything, please help

For some reason promoting my second blacksmith to an engineer fixed the issue with the blackmith

Reduce the range of tasks of masters. Maybe it’ll work.
Close mining, building and collecting items for craftsmen. Maybe it’ll work, but I don’t know.

There’s a chance that the old blacksmith (now engineer) was stuck on a recipe which couldn’t be completed, and was using up all of the CPU memory trying to complete the task. When the blacksmith was promoted, the task was dropped from the queue, freeing up memory for everything else.

It’s really weird that a task would bottle-neck the entire memory like that though; usually when a task can’t be completed the game bumps it to the back of the queue and gets on with the next one. The only thing I can think of that would cause that result would be if the in-progress task was really, really big and simply remembering it was keeping a lot of the memory busy.