I checked the entire tour before release against all supported sims (FDS9, FSX, XP9, and XP10) with a tool I wrote a couple of years ago (but only the XP10 database could change over time; the others are "static"). At the time I found no errors, so all ICAO codes should be present in FS9 as well. I am firing up FS9 on my laptop as I write this, because my true FS PC is disassembled at the moment. That takes a while, so I have plenty of time to type you an answer

LFSD is present in my "virgin" copy of FS9, see LFSD.jpg You can just see LFSA listed on the top line in that same jpg.
I have checked and found LFLL in the same way.
LFDY, should not have been in the leg list. I should have replaced that one with LFCS as I discussed with Peter at the time. That was for this very reason: it does not exist in FS9... Apparently, I let that one slip through; apologies for that!
I modified the tour legs, but I am not sure what will happen with FL for those that have already assigned themselves this tour, when they get to leg 19. As there is just more than 10 nm between the two, FL will not accept landing on the one airport as having arrived at the other.
The only solution for all that fly FS9 I see at this moment is to fly to LFCS, and file a manual PIREP as if you flew to LFDY. Those that fly FSX or up, can fly to LFDY, as assigned, as it is in their scenery.
Other option is to un-assign and re-assign the tour, but that would erase your record of having flown the legs you have flown thusfar. So that would probably only be an option if you have only just started the tour.
But then there is still the other three airports that really should be in your default scenery, Franz. It looks like there is a different problem with your install, I'm afraid. No clue as to what, though ...