i can't add anything new to my forum

i have two forums here. i wanted to upgrade one of them with some custom additions so i was checking available skins in ACP in my other forum. i had to save the skin on that forum for a second to get one special button and a while later i brought back the old skin of this forum.

the other day i wanted to add some custom buttons to my other forum, the one with saved skin on it. and now i can't. anytime i try to change anything the skin of my forum changes to the one saved for one minute. when i delete custom buttons it comes back to normal. how to add buttons without the skin change?

Have you used Themes management => Export your skin?

no what to do with it?