Have used Codebook on my iPhone for years, have never had a problem syncing to my backup in dropbox. Installed the Windows version and can not sync the Windows version to my iOS version.
I use the QRcode to transfer my sync key from my phone to my computer. When I tried to sync on my computer, I get the following error message: “Another cliet is synchronizing, please try again when it completes.” Trying to sync on my phone at this point produces a similar message.
I renamed the Zetetic folder in dropbox, sync’ed from my phone (to recreate the folder), looked at the folder in dropbox and noticed that there is a “sync” file with “… conflicted copy …” in the file name.
Tried to sync again on my computer, and got the same error message as before.