DB Error: selectList query failed

SELECT DISTINCT projects.*, projects.title_cs AS title, projects.title_cs AS name, projects.uri_cs AS uri, projects.excerpt_cs AS excerpt, projects.description_cs AS description, image.full_name AS image FROM projects LEFT JOIN project_category_relations ON projects.id = project_category_relations.project_id LEFT JOIN (SELECT object_id, file_id, CONCAT(name, '.', ext) AS full_name FROM file_attachments LEFT JOIN files ON files.id = file_attachments.file_id WHERE channel_id = 4 AND main = 1) AS image ON projects.id = image.object_id ORDER BY name

Got error 28 from storage engine