"protocol version 0 is unsupported" error message


Ever since last week when I try to sync my Codebook on my cell phone with my Codebook on my laptop over wifi I’ve been getting this error message: “Protocol version 0 is unsupported.” I have always been successful in syncing over wifi, but it’s no longer working. Any suggestions for how I can address this error?



Thanks for using Codebook and posting, although I’m sorry to hear about the sync trouble.

Could I ask what platforms, what versions of Codebook, and what OS versions you’re running (i.e. Codebook for Windows [3.0.20] - Windows 10, Codebook for iOS [3.3.4 (529)] - iOS 10.3.1).

I’ll be happy to provide further instructions if you’re unable to locate any of this information.




On my cell phone I use Android 7.0 (on a Samsung Galaxy Note 5), and on my laptop I use Windows XP.

Codebook on my XP laptop is version

Codebook on my Android cell phone is version 3.3.2



Could you please try updating to the latest version of Codebook for Windows ( when you have a chance and let me know whether it allows you to sync again? Thanks!



That fixed the problem! Thanks so much for your speedy help.



Excellent! Glad I could help.

There’s a preference within Codebook for Windows which enables an automatic check for updates. It can be found under File → Preferences → “Automatically Check for Updates”. Codebook should then prompt you when a new update is available (next time you open it).

Please feel free to reach out again if you have any further questions, issues or feedback.

Thank you again for using Codebook and have a nice day!



Interestingly, I had already selected that option to automatically check for updates… but it didn’t seem to be happening. But anyway, my sync worked fine now, so I’m good.
Thanks for your help.



There was an issue some versions back which required manually upgrading: Codebook for Windows Update 3.0.5 - Manual Upgrade Required this may have been the reason it wasn’t registering. But glad to hear everything’s working as expected again. I’ll try to reach out to you again after the next Codebook for Windows update to ensure that you’re receiving the notifications properly.