Hi Chief,

If you try to start an upgrade using gems when all your builders are busy, those gems will be converted into the resources you need for the upgrade, but the upgrade cannot start as long as no builder is available.

I fully understand if you're frustrated and upset, but this is how the game works for everyone at the moment. On the upside, you will find that your storages now contain a lot more gold or elixir than before -- in fact, they should contain exactly as much as you need for the upgrade. As long as you don't spend or lose these resources, you will be able to start your upgrade as soon as the next builder becomes available.

I'm sorry about any inconvenience this caused you, and I will make sure your experience gets passed on to the game development team. They are always happy to consider any improvements that will make the game more enjoyable