Can't return outside a subroutine at ./LabelMe/annotationTools/perl/fetch_image.cgi

Ubuntu 16.04 LTS. Install went ok, all apache mods required have been enabled. Image appears on page load, but then the page returns an error: Fatal: there are problems with fetch_image.cgi

Apache logs show the following:

[Thu Jun 07 13:07:41.886343 2018] [cgi:error] [pid 1427] [client 127.0.0.1:44032] AH01215: [Thu Jun 7 13:07:41 2018] fetch_image.cgi: Can't return outside a subroutine at LabelMe/annotationTools/perl/fetch_image.cgi line 49.: LabelMe/annotationTools/perl/fetch_image.cgi, referer: https://localhost/LabelMe/tool.html?collection=Shoes&mode=i&folder=Shoes&image=image.jpg

I've installed libcgi-session-perl and restarted Apache, but that didn't do much of anything.

Any other suggestions?

Start with LabelMe/annotationTools/perl/fetch_image.cgi at line 49 and compare the reported Apache CGI error with the script's surrounding context. Check whether the installed CGI dependencies and Apache configuration affect execution. Done means the image page loads without the fetch_image.cgi fatal error and the Apache log no longer reports the return-outside-subroutine failure.

Written by the indexing model from the issue text.