The applying of already posted G/L Entries aborted with an error message.
as of Business Central 18
If errors were displayed in the Posting Preview and the Posting Preview was called again afterwards, the error message "The record in table Gen. Journal Line already exists." was displayed.
If the G/L Account for the application was specified as Bal. Account and an amount was also specified, the filter on positive for the open entries was set incorrectly when selecting them via the NCGLA Applies-to Doc. No. field.