I received the error below, after clicking on ZZ Tuelz.
After closing and restarting, it was ok.

Kelvin

Traceback (most recent call last):
File "C:\Xi\tuelz\core\webs.py", line 178, in do_GET
File "C:\Xi\tuelz\core\handlers.py", line 119, in handle
File "C:\Xi\tuelz\core\handlers.py", line 127, in traverse
File "./zz.mod/zz/zztuels.py", line 615, in default_action
File "./zz.mod/zz/zztuels.py", line 939, in publish
File "C:\Xi\tuelz\core\databases.py", line 152, in <lambda>
File "C:\Xi\tuelz\core\databases.py", line 51, in make_query
DatabaseError: cannot start a transaction within a transaction