Hi Marc,
Do you mean solved_date in table core_solved_index has been added by a 3rd party item?
The error persists even when disabling all 3rd party items and a background task is stuck on one specific forum with "Rebuilding solved statistics for forum [name]"
Error log is flooded with :
SELECT AVG(core_solved_index.solved_date-forums_topics.start_date) FROM `forums_topics` LEFT JOIN `core_solved_index` ON core_solved_index.app='forums' AND core_solved_index.item_id=forums_topics.tid WHERE ( state NOT IN('link','merged') ) AND ( approved NOT IN(-2,-3) ) AND forum_id=25 AND start_date > 1390911377 AND start_date < 1396051140 AND core_solved_index.id IS NOT NULL
BIGINT UNSIGNED value is out of range in '`schq_prd`.`core_solved_index`.`solved_date` - `schq_prd`.`forums_topics`.`start_date`'
The forum in question is of type "discussion", so why is the system even querying for solved dates?