I noticed yesterday that for several work cycles the Frisian brick kiln consumed wares but produced no bricks.
I am not certain if this is a bug or something with my setup or if it affects other producer and other tribes.
In this case I was short of bricks, mainly as I had not expanded far enough to mine coal. I was building a new woodcutter and as I had an excess of barly decided to start a baker and a well to supply him, it was then I noticed the brick shortage and reduced the demand for all building sites to 0 bricks and I removed the road to the bakery so the builder would miss it out of the buils list, the woodcutter brick requirement was left at 1 as logs were needed for coal production. I reduced log uses so the charcoal burner was getting well supplied and every few minutes coal went to the kiln, the coal, clay and stone were consumed but nothing was produced. Eventually the blacksmith made a hammer and I got a second builder who demolished a military site to free some bricks, but still no bricks were being produced. I reconnected the bakery build site to the economy and bricks were produced again.
It seems as if the production site had allocated its next production to a site that was removed before the wares were actually created. As the site still existed it stayed at the top of the demand list although it was not in the economy with the producer so the wares had nowhere to go and were 'lost.' The same problem could occur with other building wares producers and could occur in other tribes, but may rely on exact timing to create the bug, disconnecting a buiding after the ware is produced means it gets reallocated, before some point in the production cycle means it is allocated to somewhere that is connected, there may only be a very short period where the bug could appear, perhaps milliseconds?