Can't craft anymore tier 3

[Kuru]

Super unlucky with assassination mission, took 20 tries. (the 2nd one)
Finished buying all research, equipment, so forth.

Next task is "Craft a piece of Equipment Tier 3" but I can't because when I click on equipment it says I'm at limit.

30k gold, 11k wood, 10k stone, 7k steel, 69 diamonds

So, what do I do?