[Solved] Only admin could see courses/class teaser

Hello, It was possible for anonymous and authentificated users to see class/course teaser. Unfortunately, this is not possible anymore and I couldn't understand what is causing this problem and how to fix it. Here is a printscreen Usually, anonymous and members can see teaser content, now they could just "subscribe to group" and the widget is truncated :-/ Class and courses' group visibility is public. Tried to make it "semi private" but still the same problem Tried to uninstall the last modules I installed (backup/migrate, Opigno Commerce App..), rebuild permissions, updated core, etc.. but the problem wasn't solved. Logs show this: PDOException: SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction: DELETE FROM {cache_bootstrap} WHERE (cid = :db_condition_placeholder_0) ; Array ( [:db_condition_placeholder_0] => variables ) in cache_clear_all() (line 165 of mywebsite/includes/cache.inc). Location: mywebsite/?q=drupalchat/poll&drupalchat_last_timestamp=1412251980 and also a lot of php notices: Notice: Undefined index: #markup in platon_preprocess_field() (line 294 of mywebsite/profiles/opigno_lms/themes/platon/template.php). Notice: Undefined offset: 3 in _menu_translate() (line 777 of mywebsite/includes/menu.inc). Found nothing on Google so I came here to ask for help :) Does anyone know how to fix this problem please?