take out a subbed base by the person that holds the sub request,

Bases need to be in different alliances before they can be killed - and then it depends on the diplomacy setting. The subbing has no effect on that. A subbed base can't fight another player base however.

Hi gamerdruid thanx for the reply. I know about the different alliances and diplomacy. I've tried different ways. The only thing left is to end the subbing, why else can't I attack the base I am subbing???

There is no other reasons that I can think of as to why a base can't be killed by a player.

If diplo isn't a reason...
You might be out of range or using a base that can't launch attacks (no CC). Or you're on a subed account.

I doubt there's some hidden feature here...

I've tried every which way its a large attack base i'm using and i put the construction yard in front and disabled the defences by selling the defence hq, and facility. i'm only two spaces away. it MUST be about the subbing. i guess i'll have to bite the bullet and drop the subing. i'll let you all know how it works out. WoW never thought i would be telling you guys anything you didn't know LOL thanx again WAR

when you go to do the attack do you see any message at all? Which world is this on?

One cannot attack any player for which they have accepted a substitution for. This rule was created years ago to curb the PVP exploit.

Thank you for clarifying that - something I didn't know as I've never needed to try to do.

sorry for taking so long, someone was nice enough to destroy 9 of my bases in the meantime. SO YES you have to END your substitution before your can attack said bases you were subbing.