Is Anyone Else Experiencing Crashes?
Suggested fix (unconfirmed): Turn on energy saving mode on your computer. If the demo allows it, press the F8 key in-game to send a bug report.

8 fixes · 8 how-to answers · Steam discussions
Suggested fix (unconfirmed): Turn on energy saving mode on your computer. If the demo allows it, press the F8 key in-game to send a bug report.
Suggested fix (unconfirmed): Verify the game files through Steam, or update your graphics drivers and run the game as an administrator.
Suggested fix (unconfirmed): Go to the very bottom lunging training and make the horse gallop a few times to fix the explosive status.
Suggested fix (unconfirmed): Assign staff to particular horses instead of the whole stable to avoid overlap. Divide stable boxes evenly between groomers to prevent them from choosing the same horses.
Suggested fix (unconfirmed): Enter and exit a building like the breeding lab to resolve the audio glitch.
Suggested fix (unconfirmed): Rename the "D3D12" file in the game directory (for example, by adding an underscore to it). If that fails, check your PC for pending system updates and restart your computer.
No confirmed fix yet. Players suggest: i tried deleting some of pervious days but it didn't seem to do anything
it worked for a day and then it stopped TT
No confirmed fix yet. Players suggest: if you have too many problems in the second competition you can enable auto-jump, but beware that your pace still has to be right!
Suggested fix (unconfirmed): Click the "Applications" note on the right side of the staff page, which looks like a stack of papers with a paper clip.
Suggested fix (unconfirmed): Upgrade your stable so you have two or more groups of horses. Then, switch the horses between groups using the "manage" option for each horse.
Suggested fix (unconfirmed): Choose the horse you want to enter in the competition to automatically load it into the trailer.
Suggested fix (unconfirmed): Go to the sale barn in town to retrieve your horse.
Suggested fix (unconfirmed): Go to the town store and check the shelf way in the back to the left of the feed.
Suggested fix (unconfirmed): Separate mares and stallions into different stable groups by using the "Manage" button or by clicking and dragging the horses. Alternatively, geld your stallions.
Suggested fix (unconfirmed): Restart your computer to fix the error. If that doesn't work, uninstall both the demo and the game, restart your PC, and reinstall the full game without the demo.