I have version 1.12-1.6.6.2 and it works just fine on minecraft v 1.12.2 single player, however on the forge server it does not work at all?

Probably because SparksHammers is only built for MC 1.12 and not 1.12.2 yet, so no surprise.
I've been neglecting this mod for a while, but I'll see about updating it for 1.12.2 soon to sort this.

Not sure if this is an issue... I'm using the latest version of SparksHammers fine on a 1.12.2 server with around 100 mods.
Will close this, but post if you can provide proof that my mod is causing the issue and I'll reopen.