The error is:
Parse error: syntax error, unexpected T_FUNCTION in /home/public_html/wp-content/plugins/archivist-custom-archive-templates/archivist.php on line 313
Issue seems to be with declaring functions inside the
preg_replace_callback() function. Quickly moving the function out and passing the callback function name as a sting (e.g. 'TAGS_callback') seemed to work but there are lots of calls to
preg_replace_callback() within the
main render_element() function.
I'll try for a more elegant solution later.