Actually I was wrong about firmware 2.1.0 — it already supports the new program structure (hence you don’t see the End Time parameter which used to be in the old type of program structure). So you don’t need to set ‘Repeat Every’ at all.
I’m not exactly sure why you are getting the ‘Check input and try again’ error. It sounds like the controller returned an error code when saving the program. Just to be able to recreate the issue, can you tell me what’s the water time you’ve set for each station?