1-click upgrade says "filesToUpgrade is not an array"

[9smiths]

I am upgrading from 1.5.4.1 to 1.5.6.2. I am using channel "local directory" since it was getting stuck at unzipping the prestashop.zip file previously.  Here is the message I'm getting:

 

Skip download and unzip, will now remove samples1 Files to backup.backup files initialized in auto-backupfiles_V1.5.4.1_20140519-160327-6bf93c91.zipw1vq6ccphtaccess table has been saved.w1vq6ccphtaccessory table has been saved.w1vq6ccphtaddress table has been saved.w1vq6ccphtaddress_format table has been saved.w1vq6ccphtadvice table has been.....

...287 tables has been saved.autoupgrade is preserved5496 files will be upgraded.filesToUpgrade is not an array[ERROR] file V1.5.4.1_20140519-160327-6bf93c91 is missing : unable to restore files. Operation aborted.

 

Can anyone help with this?