I have the same problem: the backup does not start and instead after the “loading…” message the Backup Log screen just displays “You have not run a backup yet. When you do you will see a log of it here” again, and the button stays at “Stop Backup”.
I’ve been through the forums and issues as well, checked that scheduled posts work (they do, and therefore wp-cron is working ok). I’ve uninstalled and reinstalled and reauthorised with Dropbox.
My backups were working fine (scheduled daily) until 4 months ago but have not worked since, whether scheduled or manually run.
Can install the cron view plugin, start a backup and post the contents of your cron here.
http://wordpress.org/extend/plugins/cron-view/
Hmmm I don’t think a backup even starts at all when I click start backup.
The cron plugin says:
Nov 26, 2012 @ 13:22 (1353936174) Once Hourly jetpack_clean_nonces
Nov 26, 2012 @ 17:40 (1353951600) Twice Daily wp_version_check
Nov 26, 2012 @ 17:40 (1353951600) Twice Daily wp_update_plugins
Nov 26, 2012 @ 17:40 (1353951600) Twice Daily wp_update_themes
Nov 26, 2012 @ 17:40 (1353951612) Once Daily wp_scheduled_delete
Nov 27, 2012 @ 2:46 (1353984411) Once Daily wp_scheduled_auto_draft_delete
Nov 27, 2012 @ 11:32 (1354015949) Once Daily akismet_scheduled_delete
Nov 27, 2012 @ 15:06 (1354028779) One-off event do_pings
Nov 28, 2012 @ 4:08 (1354075716) One-off event execute_instant_drobox_backup
I figured out that this is an incompatibility with W3 Total Cache: if I deactivate that plugin then the backup completes fine.
I’ve run both plugins for a long time together without issue, so it seems somewhere around July there was an upgrade to one of them that brought in this incompatibility.
I thought the same thing mikeprince but I got one further back up and then they continued to fail again, I purchased the error reporting email plugin and this is what I received
A fatal error occured: Forbidden. Your app is making too many requests and is being rate limited. 503s can trigger on a per-app or per-user basis. All I was doing was backing up my blog daily. Since then nothing has worked.
I still haven’t had this question answered either by the developer or by dropbox…
There is a known compatibility issue with W3TC that I am looking into.
The rate limiting is a separate issue to the one listed here, please create a new topic.
Cheers,
Mikey