Error !

AttributeError: 'Undefined' object has no attribute 'content'

% endif % if (param.path == '/yc' or param.path == '/rdsh') and 'default' in param.keys and param.default is not None: ${default.content} % endif % if '__top__' in param.keys and param.__top__ is not None: <br />${param.__top__.content} % endif
/var/web/www/templates/mako/directory/show-directory.html, line 223:
${default.content}
/usr/local/lib/python3.9/dist-packages/mako/runtime.py, line 947:
callable_(context, *args, **kwargs)
/usr/local/lib/python3.9/dist-packages/mako/runtime.py, line 920:
_exec_template(inherit, lclcontext, args=args, kwargs=kwargs)
/usr/local/lib/python3.9/dist-packages/mako/runtime.py, line 878:
_render_context(
/usr/local/lib/python3.9/dist-packages/mako/template.py, line 478:
return runtime._render(
/var/web/www/directory.cgi, line 87:
return data.tpls.get_template ('mako/directory/show-directory.html').render_unicode (param = data.locals)
/var/web/www/directory.cgi, line 356:
html = handler(DATA, ah, fd)