A very bad crash was experience. Cause was related to too many users on the site and an interaction with view Meetings/toc. Many users were going through the Meeting button and due to large number of database calls (we updated all meetings between Brisbane meeting and bioem2013) to display past meetings the site was slowing down considerably.
Attempted fix was to comment out code doing the display. To do this I had to create a new function (in jc_abstract for convienience calle jc_meetings_list). Unfortunately, I used same url for this bit of code and when the page was displayed, the website crashed extremely hard. I attempted to reverse code, but no way to access the admin pages. I used myPhpAdmin on cpanel at siteground to clear cach by dropping tables, but should have truncated the tables as it turned out. Three cache tables were deleted and database threw many errors afterwards when site was accessed. I upgraded server to 50GB and more memory. I sent email to ebea mail list, but phpList may not have worked through the server upgrade.
Technical staff at siteground worked most of the night with me to recove the lost tables from a backup. The website reappeared but the links were all pointing to page not found. They recommended that we revert to yesterday's backup, so I attempted to repair the database. I truncated the cache tables and the view_object_cache table. No effect. Problem was with views module.
set status bit of views module in database to 0 then
modified settings.php in /sites/default folder
$update_free_access = TRUE
$update_free_access = FALSE
reset permissions on file, then set status bit back to 1.
Voila, almost everything back to normal. Appears front page rotating banner block disappeared. need to activate in blocks perhaps.