I installed a fresh installation of Moodle 3.4rc1 (Build: 20171103) today. Once the installation was completed, I immediately click Dashboard > Site administration > Language > Language packs, and got the following error message dialog:

Syntax Error

Unexpected token < in JSON at position 0

The error message varied each time the page was reloaded. Sometimes it would just say "Undefined".

When I repeated the process with debugging set to DEVELOPER, additional stack trace information was made available:

{{SyntaxError: Unexpected token < in JSON at position 0 }}

{{at parse (<anonymous>) at Qb (http://localhost/moodle34/lib/javascript.php/1509831445/lib/jquery/jquery-3.2.1.min.js:1:74283) }}

at A (http://localhost/moodle34/lib/javascript.php/1509831445/lib/jquery/jquery-3.2.1.min.js:1:77810)

at XMLHttpRequest.<anonymous> (http://localhost/moodle34/lib/javascript.php/1509831445/lib/jquery/jquery-3.2.1.min.js:1:80414)

This happens while the screen is loading - before I've had a chance to do anything else on thus screen. I repeated the process with both BOOST and Clean themes but got the same result.

My environment includes Apache 2.4, PHP 7.0.24, MySQL 5.6.38. My web browser is Chrome 61.0.3163.100 (Official Build) (64-bit) for Windows. The only warning during the installation of Moodle was that I am not running on https.

Let me know if you require any additional information.

Best regards,

Michael Milette