I'm getting the following error when I try to enroll new users manually (just after clicking on the "Enrol users" button):
Unexpected token < in JSON at position 0
SyntaxError: Unexpected token < in JSON at position 0
at parse (<anonymous>)
This is a fresh-installed Moodle. I've even tried removing the whole "moodle" folder, downloading the code again and setting up a new "config.php" file to be sure no changes had been added to the original files; I had no success though. I've found several related-topics in the forum, like this, but none of them provides a satisfying answer.
Thanks so much in advance.