Going into stage 1 of FA i noticed both my OC and DC are gone when they were still under contract, what's the deal with that?

maybe retirement or they have been poached or their contracts expired :)

Most likely poached. During free agency, you can sign a coach from another team to a promotion (OC or DC to HC, or position coach to OC, DC, or HC). I think the only exception to that would be if they just resigned a contract in the previous season, but I'm not 100% sure.

Normally don't reply to threads in the community areas, but I guess I should from now on :)

What has probably happened is that either the coach has retired, or has been "poached" by another owner in the league to fill a vacant coach position that they had, or to replace a coach they have wanted to fire.

If it is your OC/DC, then my advice would be to check your leagues' "Trans" tab and possibly filter for just coaches to see what coaches have moved. Unless you remember their names, you may need to do some searching through each coach and their coaching history, but eventually, you should find them, and see where they have gone. If they have retired, then it should show on your teams' "Trans" tab that they have retired (it may not show on your teams' tab if they signed with another team)

Also, the most logical answer, as someone else has said above, your OC and DC are most probably now either retired or are a Head Coach, since OC/DC don't accept contracts to go down to position coaches, they only want to go higher (i.e. to a Head Coach position), so you can even check the other Head Coaches and see if they are there.

...or.
One could resign all coaches worth keeping by +1 $ the day after EOS sim and block the poachers...
I know nothing and every something i know someone probably already mentioned it.
I claim absentia.
:P

Honestly......you shouldn't concern yourself with coaches at all except the head coach which gives you both offensive and defensive play books.

Poaching is useless unless its to sign a new head coach.

When I lose a coach, I filter the unemployed and sort by age then sign the youngest regardless of rating.

I wish the coaching meant more and years ago I concerned myself with having the highest rated at every coaching position but its more of a cosmetic addition to the sim with possible future (years and years into the future) ramifications.

Long story short, don't sweat coaches....they aren't important and I've won plenty with horrible coaches