Please, note that, as "weird" as it may sound, 99% of all the problems some people are having with this game is that their burners/media combination don't produce DL disc that the wii likes.
It is VERY encouraged that you try at least two different brands of quality media on your burner. If it fails, try REALLY HARD to find another burner (from a friend or something) where you can make a copy of your DL disc, also in at least two different brands of media. I won't even go into trying different speeds, as only 2,4X (for old media/and-or/old burners) and 4X (for new media on new burners) are recommended. Given a choice between DVD-R DL and DVD+R DL, choose the later. They both work for some people, but most people with problems still not solved have only tried -R media.
After you tried all this, you may start to suspect something else wrong.
Please note that even the dumper of this game got it to play fine on you d2ckey, as has many other people (AFAIK), and it's 100% confirmed working on all wiikey 1.9g, even with people that first got #001 errors or couldn't boot MANY TIMES until the tried a media/combination that worked for them.
You can check their experiences on this thread:
http://gbatemp.net/index.php?showtopic=74432
Please note that, due to firmware design, all wiikey 1.9g wii's are running at 3X reading speed regardless of the configuration settings (it ignores them, unlike 1.9b firmware revision). At low reading speeds, the wii may have a bit easier time reading "bad" dvd9 burns. D2Ckey and other chips don't have this "limitation" and run at 6X reading speed. Better quality burns are necessary for those wii.
Please note that not all wii's are able to read discs as well. A marginal DL burn may work on one wii and may not work on others. Here are two articles describing how SOME wiis may have problems reading dual layer discs (while other don't).
IGN: Nintendo to Clean Japanese Wiis Over Smash Bros. Errors
Nintendo blames this on "dirty lenses", but the truth is that the laser in some wii's is tuned from the factory a bit too low for reliable dual layer operation. Here is a link to an article about it from MONTHS AGO (this is not a "new" problem, it's just the first time a dual layer wii game's been released):
http://www.cyclopswiz.com/ (scroll down just a bit, to where it says "upgrade 3.5" and read the next 3 or 4 short paragraphs)
This is even worse on RECORDEABLE DL media, as it has MUCH lower reflectivity than pressed ORIGINAL media. To try to avoid problems also, Nintendo used for this game a top quality GOLD layer pressed disc, that has even higher reflectivity than the silver discs. The highest in the industry.
So please, again, before you bang your head agains a wall, try to get hold of a different burner and try once more with good media. There is no one recommendation of what "good media is". The only one recognized as truly good is a Verbatim DVD+R DL that has written in the label 2.4x-6x and that says made in singapore. Please note that if it says made in india is just as crappy as any other, so avoid. The Verbatim labeled 8X is a DIFFERENT media, but also known to be good in new burners, but not as good as the other. Again, given the choice, use +R instead of -R. Try brands like japanese Sony, TDK, Fuji or Taiyo Yuden, others like Kodak, and some people report good results with the taiwanese maker Ritek (ridata) on newer burners.
Also, as a general rule, burners older than about 2 years do a crappy job on dual layers, as do laptop burners older than about 1 year. There are exceptions, of course, specially on some Pioneers that did very good on DL. If you'd like to get a new burner, there are plenty for around $40 and virtually all modern ones do a decent job on DL recording. Some models by Pioneer (but not all their models) and some Samsungs (but not all) have very favourable reviews.
Also, sometimes, some burning software screws up with some burners/media combinations, although this is rare. Imgburn, clonecd and Nero, in their latest versions, are recognized to work just fine for Wii isos. But if you suspect your recording program, you may want to test at least two different ones. Nero and clonecd have free time-limited evaluation versions for download. Imgburn is free to begin with.
Please note that too-low of a recording speed can also be as bad as too-high of a recording speed. If your burner is old, it may not be able to properly handle fast formulated new media (because it wasn't even "invented" when the burner was made). Try to get media labeled at slow speeds (older media) to be used with old burners (older than about 1.5 years). These burners can not burn on hi speed anyway, and their recommended recording speed is 2.4x. If you have a new burner, say one that is 12X DL capable, it all depends on the media. On these burners, the recommended speed for old media is also 2.4X, but for new media it's 4X, NOT 2.4X. So:
Fast new media on a new fast burner=4X
Slow old media in a new fast burner=2.4x or 4x, you have to try.
Fast new media in an old slow burner=may not work right no matter what you do -- try updating your burner's firmware.
Slow old media in an old slow burner=2.4x
If all fails, you may need to clean up your wii's lense or tune your wii's laser a bit (check link above on how to do this) to see if you can read DL media without problems.
Also, please note that you must have your wii updated to the 3.1u version of the firmware (if you are in USA NTSC-U region) or to 3.1e (Europe PAL region) before trying out this game (japanese NTSC-J wii's don't have to worry about this). You can check this on the configuration menu of your wii. If you are not, you MUST connect your wii to the internet and accept the updates. If you can not connect your wii to the internet, you may obtain those updates if you have an european PAL wii by running the game Donkey Kong Jet Racer (PAL) or Wii Chess (PAL) without using brick-blocker, of course. Sorry but I don't know of games that carry the 3.1u update for the USA wii's. But always check on your wii menu to see if you are updated to 3.1 for sure.
Once you do this, remenber that the smash bross game will still not work unless you let it run the included updates (even if only til 15%). If you never run them because you always produce brick-blocked copies, then it will never work.
And that if your modchip doesn't have multiregion support enabled, then it will also not work unless you use regionfrii (most chips have it enabled by default, except wiikey, where it's enabled by running the configuration disc)
And remember that running the updates may mean that you'll end up with duplicate channels on non-japanese wii's unless you resort to the 15% "metroid" trick.
Or maybe your problem is different, in which case don't hesitate to ask giving as many specific details as possible to see if someone can figure it out.