Please, use <code>...</code> tags to show your code. How did you install WWW::Mechanize::Firefox? How did you install MozRepl::RemoteObject?

Do you have all of these dependencies installed?

$ cpanm --showdeps WWW::Mechanize::Firefox
--> Working on WWW::Mechanize::Firefox
Fetching http://www.cpan.org/authors/id/C/CO/CORION/WWW-Mechanize-Fire
+fox-0.66.tar.gz ... OK
Configuring WWW-Mechanize-Firefox-0.66 ... OK
Scalar::Util~1.14
WWW::Mechanize::Link
HTTP::Daemon
Task::Weaken
Shell::Command
Object::Import
LWP::Simple
parent
URI
ExtUtils::MakeMaker
WWW::Mechanize
HTTP::Cookies
URI::data
HTTP::Date
MozRepl::RemoteObject~0.31
perl~5.006
MIME::Base64
HTTP::Response
HTML::Selector::XPath
File::Basename
Cwd
[download]