The transaction did not generate WIP.

Check to see if the transaction is in the new.blt file:

1. From the Billing Inquiry menu, select Transactions
2. Click on the condition button or icon and add a condition of Job Equal To xxx (xxx is the job ID)

Note: Do not use contract as a condition in Billing because if the transaction rejected due to "contract unknown" there will not be a contract id on the entry in Billing.

If the transaction is still in the new.blt, you must Generate Work-In-Progress (Tasks menu). Condition on the Job ID This task is used to apply rates and markup calculations to cost transactions received from Accounts Payable, Equipment Cost, Job Cost, and Payroll for billing purposes. Work-In-Progress (WIP) records created for cost-based billings are stored in the Unbilled.BLW file.

Review the Generate WIP journal to verify that the transactions generated or not.  See the attached articles for help with rejections.  "Error:  "Rejected Contract Unknown" (contract link is incorrect" and "Error:  "No markup table for rate calculation.".   For an explanation of the cost based workflow, see attached article "What is the workflow for cost based billing?"