ok thanks, I added it exactly as you said it works!
turns out there must be a problem with my sql-ledger since the upgrade because it's that that gives a 500 error. So now at least I know the perl part with apache is working!
thanks for you help, I'll post back when or if I can work out why my perl code is refusing to work after the upgrade. I get 500 error on my login.pl, has not been changed and worked before. I wonder if the imscp upgrade removed some packages or dependencies? Not sure it ever worked on the command line but just tried it since running it in a browser just results in 500 error and nothing in logs of any use.
perl login.pl
Can't locate bin/xterm/login.pl in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at login.pl line 120