When trying to record data in Live Entry, some data options are not in the drop down list but others are, e.g. choosing a sire and not all sires are listed.
Example: A Sire you wish to choose is not in the drop down list
Go to Setup > Session defaults and select the Restricted Lists tab.

Ensure that any sires you wish to use, are not in that list. If they are, select the sire and hit remove.
This will bring the sire back as an option to use for data entry in Live Entry
Article ID 1899