Budget exceeded in CJ32

HI

getting Below Error

Item WBS Element XXXXXX Budget exceeded

Message BP604

When User wants to release the Budget in CJ32 he get the above error

they do Bottom up budget, Period Wise they have assigned the Budget

At first level after total up budget is 90laks, they have released only 16lak, this month they are trying to do release balance amount of 74lak

thy could not able to do, system say budget exceeded

in cj32 when its checked assigned value was 2 cr's which is more the release budget

WBS 4 level XXXXXXX Budget 1687000 Assigned 1005276

WBS 4 level XXXXXXX Budget 1900000 Assigned 18466080

WBS 4 level XXXXXXX Budget 4600000 Assigned 264621

WBS 4 level XXXXXXX Budget NA Assigned 1725420

First thing how system allowed to do commitment/actual booking more then the released Budget when Availability control was active

Kindly advice what are all the changes need to be done

Thanks