Prestashop front-end stuck in maintenance mode ?

Back-end says shop is enabled but front-end is stubbornly stuck in maintenance mode ? Going crazy ? Don't panic!

Look into your Prestashop database, specifically the ps_configuration table.

select * from ps_configuration where ps_configuration.name = 'PS_SHOP_ENABLE';

You might get something like this:

+------------------+---------------+---------+----------------+-------+---------------------+---------------------+
| id_configuration | id_shop_group | id_shop | name           | value | date_add            | date_upd            |
+------------------+---------------+---------+----------------+-------+---------------------+---------------------+
|               30 |          NULL |    NULL | PS_SHOP_ENABLE | 1     | 0000-00-00 00:00:00 | 2015-04-17 13:24:22 | 
|              476 |          NULL |       1 | PS_SHOP_ENABLE | 0     | 2015-04-12 22:46:19 | 2015-04-12 22:46:19 | 
|              477 |          NULL |       6 | PS_SHOP_ENABLE | 0     | 2015-04-12 22:46:19 | 2015-04-12 22:46:19 | 
|              478 |          NULL |       7 | PS_SHOP_ENABLE | 0     | 2015-04-12 22:46:19 | 2015-04-12 22:46:19 | 
+------------------+---------------+---------+----------------+-------+---------------------+---------------------+

As you can see only one is enabled, other shops are not. The quick fix,  

update ps_configuration set value=1 where name='PS_SHOP_ENABLE';

should do the trick.