I was working with my gallery uploading folders+files and after the syncronization I got an SQL error when I come back to the gallery. Before the syncronization I make a try withouth changing nothing in the database and everything was ok (no error message).
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The message I get is
Warning:  [mysql error 1030] Got error 28 from storage engine
SELECT c.id AS cat_id, global_rank,
  MAX(date_available) AS date_last, COUNT(date_available) AS nb_images
FROM piwigo_categories as c
  LEFT JOIN piwigo_image_category AS ic ON ic.category_id = c.id
  LEFT JOIN piwigo_images AS i
    ON ic.image_id = i.id
      AND i.level<=8
  GROUP BY c.id, c.global_rank in /share/MD0_DATA/Web/dcodeIMG/include/dblayer/functions_mysqli.inc.php on line 834
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Fatal error: Call to a member function fetch_assoc() on a non-object in /share/MD0_DATA/Web/dcodeIMG/include/dblayer/functions_mysqli.inc.php on line 181

To understand if the problem is with some files I've empity the galleries folder and now piwigo works again except for the "user administrator" when I try to go there I get this one:
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Warning:  [mysql error 1030] Got error 28 from storage engine
desc piwigo_user_infos in /share/MD0_DATA/Web/dcodeIMG/include/dblayer/functions_mysqli.inc.php on line 834
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The real strange thing is that I run piwigo on my Q-NAP that acts also as server, where I've installed phpmyadmin. Copying all my photos from Q-NAP on my MAC everything works fine. So I really can't understand where the problem is.

Anyone can help me?