Craft files and DB out of sync A client's site is currently showing this message: 


  Craft does not support backtracking to this version. Please upload
  Craft 2773 or later.


I understand how to fix it, but I don't understand how it's happened.

In Craft’s request log I can only see one update:

2016/02/22 15:37:15 [info] [application] [Forced] Updating from 2.5.2761 to 2.5.2763.


But in the craft_info table the version and build are 2.6 and 2773, updated_at 2016-03-09 22:07:49.

Also in the log are several requests hitting 404s - /wordpress/, /administrator/index.php, /wp/, etc.

Then at 2016/03/10 04:07:42 (6 hours after craft_info was updated) in the log I'm seeing a load of these errors:

******************************************************************************************************
2016/03/16 09:11:25 [error] [exception.Craft\HttpException.503] exception 'Craft\HttpException' in /chroot/home/lincshub/lincshub.com/craft/app/etc/web/WebApp.php:229
Stack trace:
#0 /chroot/home/domain/domain.com/craft/app/framework/base/CApplication.php(184): Craft\WebApp-&gt;processRequest()
#1 /chroot/home/domain/domain.com/craft/app/index.php(62): CApplication-&gt;run()
#2 /chroot/home/domain/domain.com/html/index.php(19): require_once('/chroot/home/li...')
#3 {main}
REQUEST_URI=/
---


The last deployment (local to production) was made on 5 Feb 2016 12:44.

Could anyone shed some light on what's going on here please?
It looks like the database schema (at Craft version 2.6.2773) is ahead of the craft/app files on your file system (at Craft version 2.5.2763).

Since (I assume) you're not seeing any update info being logged in production around 2016-03-09 22:07:49 (from the dateUpdated column in the craft_info table), my guess is that someone updated the site/database locally, then restored the updated database to production with the older files still in place.