Kaalos

I can't seem to buy linden's from my SL account???

I've tried to buy a neko pro Clothing Locker for 139 L$ and I can't, it gives me an Error that Market Place can't make cahnges to this invoice at this time. I can't correct it with a hard refresche <Ctrl> F5 and the error continues. I need MP, I'm a dancer with the mouine rouges and am very concerted I won't be able to put my costumes together intime to be ready for the show. PLEASE HELP!