I had the same error today. Data from my iphone was not synced back correctly on my mac after i woke up the mac from sleep.

I sought out the corresponding zip file and compared the different copies on my local disk an on the idisk. The local file was only half size and was corrupt (unzip was unable to open it) while the idisk file could be copied to my mac and opened without a hassle.

Thus i simply moved the good copy of the file into the OmniFocus.ofocus folder on the local disc and started OF.
So far everything seems to be fine, the changes i made on the phone are shown correctly on the Mac.

I'll try further syncing now....

Edit: Several syncs later everything is working fine so far. Holding my thumbs...

Leanda was kind enough to send in her data, and she had the exact same problem. We're in communication with Apple, and we'll make some changes on our end to account for this. Sorry for the trouble.

I've had this same issue multiple times recently. How can I prevent this from occurring. It's very frustrating because it occurs on my work Macbook, so that I don't have access to my tasks during the workday - until I get home and fix the issue. Thanks.

You might see if using the Omni experimental sync server eliminates this issue for you. See the thread at [url]http://forums.omnigroup.com/showthread.php?t=15967[/url]

Same problem
 

After several years of flawless use with both local and OmniSync server syncs I encountered this problem also last night.

Following the instructions I went to the location of the zip file on my HD and removed it (size was Zero bytes). After that OmniFocus was able to start again and correctly sync with the iPhone and iPad versions.