Polymerization not working

[Kouga]

I'm just wondering what I might be possibly missing.

1. Enemy field is empty (as in, no spells/traps to prevent spells on my side from working)
2. I got the required amount of monsters for a specific fusion on my field or my hand (both on field or both in hand)
3. Polymerization is in my hand.

Now what I expected would happen:
- I activate the card, I choose the fusion materials, they get destroyed, my fusion monster gets summoned and I wreck my enemy throughoutly.

What happens:
- I can't even activate Polymerization

Fusion: Ancient Gear Howitzer
Required: 2x Ancient Gear (tried with the literal "ancient gear" and cards just named "ancient gear SOMETHING")

Any idea?

[This is a house]

Is your opponents field empty in this situation, or are there no spells or traps?

[Kouga]

Monsters yes, field/spell/traps no.

(Also worth mentioning: yes, the fusion monsters are in the extra deck)

[This is a house]

So what are the effects of those monsters?

[Kouga]

Nothing that would prevent fusions from happening or spells from being triggered. Every (!) other spell works just fine.

[Dark Alan]

Ancient Gear Howitzer
Card Text
2 "Ancient Gear" monsters
Unaffected by other cards' effects. During your Main Phase: You can inflict 1000 damage to your opponent. You can only use this effect of "Ancient Gear Howitzer" once per turn. If this card is destroyed by battle and sent to the Graveyard: You can Special Summon 1 "Ancient Gear" monster from your Deck, ignoring its Summoning conditions.

It should work in both cases, probably a bug?

[Kouga]

Wellllll.. turns out activating the seal of orichalcos before trying a fusion isn't the best of ideas. I didn't pay attention to the card's text - it's explicitely mentioned too. Discovered my absolutely dumb mistake about 2 minutes after your reply.

Guess someone's going to curse later this day~

Thanks for the help :)

[Dark Alan]

Haha yeah, if I remember right, The Seal of Orichalcos doesn't allow extra deck summons

[Kouga]

(In fact I played it without even thinking about it =.=' Good grief.. Really thought it hadn't been in play when I posted .. but given the fact it works just fine without it and the enemy didn't change, in all likelihood I had played it when fusions didn't work)

[Dark Alan]

I have the card in real life, then I made a deck with tons of synchros and fusions, and realized, sh1t, I can't have this in my deck haha. Happens bro