OmniFocus 2.1.1, iPhone 5S 7.0.4, always requests a password for the sync server, never syncs and continues to ask for the password.
Have deleted the app via iTunes. Restarted, then restored. Same thing.
Opened new Omni Sync account. Problem still there.
Have replaced the sync settings on both the iMac & iPhone.
Changed the password several times.
It’s as if there is an authentication error being generated at either the iPhone end or the OmniSync end.
It seems like you’ve input a wrong account or password at one time. It’s still in your keychain, so there will be a crash between the right one and the wrong one.
###HERE is a way to solve it, it looks effective.
Open “other” on your launchpad.
Open “keychain”.
Search “omni” , find and delete the wrong account or password.
Then it will be OK.
And sorry for my poor English.
I’m having the same problem on my iPhone and iPad. I deleted the Keychain entries on my MacBook Pro OSX Mavericks but the problem still exists. The desktop app has never exhibited this problem.