Tassilo Horn <tassilo@member.fsf.org> writes:
> Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
>   replace-regexp-in-string("[ 	]zz_mairix-searches-1:[0-9]+" " searches:57788" nil t t)

Thanks for the backtrace. The code stumbled upon a message with no Xref
header. I wouldn't know why this happens for many search results - seems
more like a coincidence. Anyway, please apply the attached patch to a
current nnmairix.el (v0.4) and tell me if it fixes the problem.

-David