diff a/lib/form/url.php b/lib/form/url.php
--- a/lib/form/url.php
+++ b/lib/form/url.php
@@ class MoodleQuickForm_url extends HTML_QuickForm_text{
        $args = new stdClass();
        $args->accepted_types = '*';
        $args->return_types = FILE_EXTERNAL;
-       $args->context = $PAGE->context;
+
+       // MDL-30869
+       $newcontext = new stdClass();
+       $newcontext->id = $context->id;
+       $newcontext->contextlevel = $context->contextlevel;
+       $newcontext->protected = $context->instanceid;
+       $newcontext->path = $context->path;
+       $newcontext->depth = $context->depth;
+       $args->context = $newcontext;
+
        $args->client_id = $client_id;
        $args->env = 'url';
        $fp = new file_picker($args);
        $options = $fp->options;

        // print out file picker
        $str .= $OUTPUT->render($fp);

        $module = array('name'=>'form_url', 'fullpath'=>'/lib/form/url.js', 'requires'=>array('core_filepicker'));
        $PAGE->requires->js_init_call('M.form_url.init', array($options), true, $module);
        $PAGE->requires->js_function_call('show_item', array('filepicker-button-'.$client_id));

        return $str;