One thing to keep in mind is that CGI.pm works just fine with mod_perl 2 and you don't need to change your code to use libapreq2 unless you want to. Now, if you do want to use libapreq2, the best place to ask for help with this error is the mailing list, which you can find at http://httpd.apache.org/apreq/.
Comment on Re: Static CGI.pm to mod_perl2 (not mod_perl)
My application works great with CGI.pm as it stands, but I wanted to turn it into a mod_perl2 application for the performance reasons (vs. using something like Memoize for example).
Or are you saying that simply using CGI.pm and its associated objects within my application, automagically makes it a mod_perl2 application?
I'm saying that CGI.pm works correctly in ModPerl::Registry and perl handlers, so you can write your mod_perl application using it. Apache2::Request is faster at parsing parameters than CGI.pm, but in real time the difference is pretty small.