But wouldn't you have thought that the cocktails are meant to replace topaz during the festival? The next mission I have to complete is to collect stone, but I can't unlock a space to be able to collect stone, so that just means I'm now completely stuck, because I can't unlock any more free expansions.
Topaz stops generating during calendar events, you have to increase your max topaz (via cards or bank investment) and make sure your topaz is full before the event starts to get the most out of them. The upgrades bought by topaz during the events are strong but not equal so make sure you understand what you're actually doing before buying all you can, I made that mistake last year then got stuck in an entirely avoidable grind. For the summer event it does seem that the land is the best thing to buy with it, the build queue and speed are not worth it and while the material gain might be, I have no idea what stack capacity is so idk, you decide!
I know, and it says that happens because it will be replaced by an event specific currency. I think it's a bug in the coding, because otherwise it's a major game design flaw and the rest of the game is too well designed for that. I wish there was a way to contact the developer to report it as a bug.