If you have removed the xibo_admin user, system-owned resources will be affected. You can run the following SQL command to change the ownership on those dayparts to resolve it:
UPDATE `daypart` SET userId = (SELECT userId FROM `user` WHERE usertypeid = 1 LIMIT 1) WHERE userId NOT IN (SELECT userId FROM `user`);
You may also need to run the SQL Command, in the below post for your Displays: