Continuity mistake: When Kochanski puts the cat in the disintegrator, it changes the way it's facing between shots and again when she takes it out. (00:11:19)
Continuity mistake: When the crew meet the alternate dimension crew, both crews are standing side by side, but when the two Listers shake each other's hands, the Cat and Kryten from both crews have disappeared.
Continuity mistake: In the Aigburth Arms, when Frank hands the box with baby Lister to the barmaid, the barmaid takes the box placing her hand on top of the box, but in the next shot, her hand is suddenly on the side of the box.
Continuity mistake: When hologram Lister has finished explaining to the crew why he is dead, the crew are standing side by side, but when Lister asks what happened to Kochanski, Cat and Kryten have vanished.
Suggested correction: Lister can only see M-Corp products and M-Corp employees. Cat is not an employee of JMC or M-Corp, so he disappears. Lister is the only member of the crew who is employed by M-Corp at this point.
Suggested correction: Cat was a descendant of the cat Lister brought aboard Red Dwarf. Would it be possible that the new owners might have stricter security controls, and Lister was sent to Stasis for a different reason?
Andy Benham ★
Inventing Deux ex machina explanations for a plot hole doesn't make it any less of a plot hole. M-Corp erases all of the Jupiter Mining Corporation's equipment, personnel and infrastructure from Lister's life. In no way is Cat a part of that. He has no connection at all to the Jupiter Mining Corporation, and until he meets him in Episode 1 no connection to Lister, either.
If M-Corp only erased JMC equipment from Lister's life, then Kryten, who belongs to DivaDroid and not the JMC, wouldn't have disappeared either. He disappears as he doesn't belong to M-Corp, not because he belongs to the JMC. Cat has no connection to M-Corp, as he wasn't a part of the JMC (as you pointed out), and is therefore erased for Lister.