There are a few places that need to be checked to see if any bills already exist with this WIP on:
Negative Unbilled WIP can prevent archiving or closing a Proclaim matter, making these checks essential for smooth matter management.
Check to make sure there isn't any draft batches sat in General Postings.
Check there are no slips in the 'Drafts' tab of Slip Postings.
Check there are no slips in the 'Rejected' tab of Slip Postings.
If there are any SIB postings in the Slip Postings then you can delete these by:
Highlighting the slip in Slip Postings on the Rejected tab.
Selecting the Delete button at the bottom of the screen.
If these are in General Postings do the below:
Highlight the SIB line on the right hand side of General Postings.
Select DELETE at the bottom of the screen.
Retry archiving or closing the matter after clearing the rejected and draft slips.