When importing a database preset, there is an SQL error by an uninitialized variable.
The error shows some like this:

ERROR: invalid input syntax for integer: ""

UPDATE mdl_data SET course .....defaultsortdir = '0',editany = '0',notification = '' WHERE id = 9

the error is in the notification variable.

For solve this we must modify the file /moodle/mod/data/lib.php
and put in the function: data_update_instance($data)
this code:
if (empty($data->notification))

before call the function:
if (! update_record('data', $data))

See you