We resolved this issue in version 7.78.687. Download the latest version from our website.
In version 7.77 the system was incorrectly defaulting the project ID on Payments. When this item is required, we intentionally do not default the Project ID so that the user is forced to choose the correct Projects.
Defaulting a value on a required field without having a way to turn this off may result in Payments getting saved/posted with Projects that the user was never forced to accept. Required Projects are never defaulted directly from the Fund record for typically data entry. Please note that many other records allow a default distribution wheras the Payment record does not.