I'm guessing your devices are connected 1G or greater, correct?
Make sure everything is set to Auto/Auto, long gone are the days where you need to hard set ports
Check all cables involved - Swap em until you no longer get the errors
If you're still getting errors swap SFPs
If that doesn't work try another switch port, they DO go bad once in a while
Not likely but possible bad port on the F5. Try another (might be hard to do without re-config though)
My money is on one of the first three..
And no, it's not normal and if you're getting a ton it can cause issues since you'll start getting a lot of retransmits..
Good luck!