I’ve had the same problem with a repairman out several times changing parts that made no difference but I’ve recently come upon a solution!
Starting with the machine being clear, no codes, move the dial where you need it, then ***gently but firmly*** press the start button. If you accidentally double tap the start button or touch 2 buttons instead of just one, you’ll get an error message. Also, once the machine is running, ***do not*** pause it as this will cause an error message.
Before I stated handling the machine this way I would get an error message at least once a wash day. Since I’ve been very careful, I haven’t had an error message in months.