It's Lorenzo asking, not me.Tom

Oops, edited my post.

Lorenzo,Your problem is, just like I told you btw, that the distance between SPL and DETSI is less than 40 miles. It is only possible to enter a fix relative to a waypoint between that waypoint and the waypoint before. So in this case: you can only enter a fix between SPL and DETSI. From your screenshots I estimate the distance between SPL and DETSI is about 30 miles, so you can't enter a fix of more than 30 miles from SPL. You can try to enter SPL/-20 and see if that works.If you still want a SPL/-40 fix, I'm afraid that you have to clear the waypoints DETSI and RIVER first. After that you should be able to enter SPL/-40.

Perfectly right Pieter, many thanks!!

For some reason, I'm unable to see the attachments in this thread. Is there a chance someone might be able to walk me through this procedure using the BARET4 STAR at KSAN? I don't quite follow the FMS manual on it.

I was told to cross 25 DME from PGY (which is omitted from the STAR when I was assigned the localizer 27 approach) at 12,000 ft. but, for the life of me, couldn't remember how to do this. Wound up pulling the airspeed and altitude knobs and descended much earlier than I probably had to just to ensure I'd make it.Thanks.