After deleting an advance deposit, you have the option to change the application post date of the credit that previously funded a deleted advance deposit by opening the credit and clicking the Applied to tab, Application History. If you change the post date and save the credit, you may receive the error: you must fully schedule the ungenerated amount.
We resolved this issue in version 7.82.104, patch 19.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.