[wp-testers] Core Upgrade Unsuccessful

[Jeff Chandler]

Well, I finally gave the core upgrade a try and thought the backup 
utility was pretty nifty. I think clicked on the button to initiate an 
automatic upgrade and was greeted with the following error:

*Downloading update from 
http://wordpress.org/nightly-builds/wordpress-latest.zip*

*Unpacking the core update*

*Incompatible archive: PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End 
of Central Dir Record signature*

*Installation Failed*

Perhaps I can't use this feature on a local server?