I'm less convinced of this one since the usage of this tag seems to less in the mode of the lolcat and more in the mode of putting the error message in the tag. By the same reasoning error, fault, and crash should also be expurgated. This tag just needs a bit of pruning.
The use-case is one of a modifier on an existing tag. A meta-tag, but perhaps a useful one. A post tagged with:
Tells you at a glance what the main problem is.
This distinguishes it from other such now-gone metatags like:
Where the meta-tag (windows) is merely an overly broad and mostly useless classifier. These tags are somewhat useful, they just need some regular maintenance to keep clean.