Budgeted units showing as zero

Dear all,

i had assigned estimation weights to all the WBS elements to my projects.

the total budgeted units for the project was 9000 units so the weightage was given for 100(which was split to each wbs element

now for some reason i hve  to remove the weightages,so in the top down estimation window i removed the estimated units(which was 100) to nil.

after applying this change the budgted units is showing as zero.

so how to bring this back to the original units which was 9000 units

 

please guide me