Thanks for your follow up Kate.

There is a new option in the Adagio JobCost company profile called 'Warn on invalid entry periods' which prevents posting transactions outside of the entered periods. Which by default are your fiscal calendar but can be edited or added to. Likely this option is turned on for Karen's company when they don't want it to be. This option was added by reqest of other people who wanted to prevent posting to particular date ranges and only only posting within certain dates.

Turning it off will allow the retainage to be posted, as would creating a new entry period encompassing the date of the retainage transaction.