error in scroll!

it is showing error while i am doing the synthesis of slider! it tells that there is no available monster for synthesis, while they are available and are also not in combat!! Can someone help me what to do!!!

are they all level 14?

All level 14 like Junico said and also make sure the havent evolved into "octomom" or others.
If they all are correct try putting in combat mode and take back out.

And you do have 2 different Antee, A Blossom, and an Octobud?