(Maybe I should have read the ISPConfig manual, but reading manuals is something I almost never do)
W00t! What a drama 🙂
I’ve been on this puzzle for hours, maybe like you too, since you probably found this posting while searching for your own problems with open_basedir restrictions on “moodledata”.
To keep things short, here is the solution:
Change the path for moodledata from /var/www/clients/clientx/webx/moodledata to /var/www/clients/clientx/webx/private/moodledata (only insert /private, don’t change anything else)