error when trying to edit plan

went to change billing on a plan and gave me an error.  when i went to look at the error. i get this message

Your request format is invalid. It contains some potentially dangerous or in valid characters like ";,',--" etc.


Error : 70100510 : Update failed; some Resources are in use.

how do i fix this.  every site i am setting up is using quarterly billing but i want yearly billing.

Such error throws by HC if any resource of the plan is been over used, . For example if Bandwidth/Disk Space is consumed more than the allocated in plan by any user then HC will not let to edit unless it been corrected.

For more detail please consult with this kb http://support.hostingc...ction=kb&article=285