Following the release of the 11.5.2 update for Dreamweaver CS5.5 (posted on 12 June 2012) we discovered an issue that, in certain circumstances, would lead to Dreamweaver crashing on Mac (note: Windows was not affected). As soon as we became aware of the problem we withdrew the 11.5.2 update for Mac and started working on a revised version of the updater.
We are pleased to announce that we have resolved the issue and have now made this available for download for Mac users – note that the new version number is 11.5.3.
Please accept our apologies for the delayed release of the update for Mac and for any inconvenience caused to customers who were impacted by this issue. We are confident that the 11.5.3 update is ready for use – you can install the update automatically using the Adobe Application Manager or you can download it directly from the Dreamweaver support page.

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here because autoupdate does not work
Yes – I received this error both from auto-update and from standalone downloaded updater:
There was an error installing this update. Please quit and try again later. Error Code: U44M1I218
See this link: http://forums.adobe.com/thread/967504?tstart=30
This links to a page that does not have the update it describes.
The linked page has a section named “Dreamweaver CS5.5″ which has the Win and Mac manual download links.
This page only has the 11.5.1 updater. Is there anywhere one can download the 11.5.3 updater. It continues to fail through Adobe Application Manager.