Why is the video not available?Edit
Yu-Gi-Oh!: The Abridged Series has always suffered from issues relating to copyright. Since the early days, LittleKuriboh's videos have been periodically taken down from his YouTube account, claiming copyright infringement as the reason. However, the use of Yu-Gi-Oh! material is considered "fair" in this case, because YGOTAS is a parody. For that reason, most times, after the issue gets straightened out, the blocked videos get restored.
Still, to this day, and even after many counter-claims and negotiations, videos sometimes become unavailable for a while, mainly due to automatic actions on the part of bots.
Many other video streaming services have been used at various points, but the only remaining ones today are YouTube and the TeamFourStar website.
Is this temporary or permanent?Edit
That depends. In the case of recent videos, it will probably be restored soon. Also, there is likely a copy uploaded to the TeamFourStar website.
However, with older videos it's usually more complicated. LK's first account, named "LittleKuriboh", was cancelled in its entirety on mid-2007, and has never been restored since. All main series episodes and movies in that channel were later reuploaded to LK's second account, "CardGamesFTW", but most of the bonus videos up to that date were not. Some of them can be found in other people's YouTube accounts, if they were uploaded there and never taken down (not a good practice, but in this case it might be our only source left). But some videos aren't really anywhere anymore.
Adding to that, some videos which were taken down from the CardGamesFTW account haven't been restored either, and probably won't be.