Allowing that much would put you over your limit | message

Allowing that much Disk Space would put you over your limit of 4000
Allowing that much Bandwidth would put you over your limit of 25000

If you get one of these messages, you are trying to allocate more resources to a client or domain than you have available.
If that is not the case, go to User Level and click the domain settings of the domains there. Most likely there are ticks next to bandwidth and disk space (Same as main account).

Remove those ticks and divide the disk space and bandwidth per domain.