Board Game Arena

I have Inscribed Blade that should give me a discount of 2 tablets on Research.

I am trying to Research and I have to pay 1 tablet and 1 jewel. I have 1 jewel but game says me that I cannot beacouse I have not enough tablets!

https://boardgamearena.com/9/arnak?table=296847199

Is it a bug or a rule?

TY

If you want to play the artifact from your hand you need a tablet to activate it. So if you don't have a tablet left to pay for the blade itself you can't use it's research discount

Thank you! I didn't see that "small" icon (LOL, second game ever form me)