When running a jcloze quiz that uses special chars, it throws the following error : Unknown method called against mod_taskchain_attempt_hp_6_jcloze_xml_renderer :: TC_keypad_char_value

And here is the backtrace :
Debug info:
Error code: codingerror
Stack trace:
line 236 of /lib/outputrenderers.php: coding_exception thrown
line 2885 of /home/moodle/plugins/mod/taskchain/attempt/hp/6/renderer.php: call to plugin_renderer_base->__call()
line 2885 of /home/moodle/plugins/mod/taskchain/attempt/hp/6/renderer.php: call to mod_taskchain_attempt_hp_6_jcloze_xml_renderer->TC_keypad_char_value()
line ? of unknownfile: call to mod_taskchain_attempt_hp_6_renderer->taskchain_keypad_chars_sort()
line 2853 of /home/moodle/plugins/mod/taskchain/attempt/hp/6/renderer.php: call to usort()
line 821 of /home/moodle/plugins/mod/taskchain/attempt/hp/renderer.php: call to mod_taskchain_attempt_hp_6_renderer->expand_Keypad()
line ? of unknownfile: call to mod_taskchain_attempt_hp_renderer->expand_block()
line 799 of /home/moodle/plugins/mod/taskchain/attempt/hp/renderer.php: call to preg_replace_callback()
line 779 of /home/moodle/plugins/mod/taskchain/attempt/hp/renderer.php: call to mod_taskchain_attempt_hp_renderer->expand_blocks()
line 183 of /home/moodle/plugins/mod/taskchain/attempt/hp/renderer.php: call to mod_taskchain_attempt_hp_renderer->expand_template()
line 157 of /home/moodle/plugins/mod/taskchain/attempt/hp/renderer.php: call to mod_taskchain_attempt_hp_renderer->xml_set_htmlcontent()
line 211 of /home/moodle/plugins/mod/taskchain/attempt/hp/renderer.php: call to mod_taskchain_attempt_hp_renderer->set_htmlcontent()
line 266 of /home/moodle/plugins/mod/taskchain/attempt/renderer.php: call to mod_taskchain_attempt_hp_renderer->set_headcontent()
line 89 of /home/moodle/plugins/mod/taskchain/attempt.php: call to mod_taskchain_attempt_renderer->render_attempt()