The new machines, released in the first week of June, have been reported to have been disconnecting users from their wireless networks, immediately followed by a kernel panic (a type of error that occurs when the core, or kernel, of an operating system receives an instruction in an unexpected format, or that it fails to handle properly). Some users have reported experiencing kernel panics as early as the moment they set up their wireless network in the initial hardware setup, directly out of the box.
Various sources at Apple have offered dozens of different "fixes" for this problem, none of which have actually solved the problem. Explanations varying from bad AirPort Cards and Logic Boards to incompatibility with specific routers to bad OS updates have been noted, however none have been officially confirmed."
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