I use Evolution only for the address-book. I use it to sync my Google address book which has extensive information from my Android phone. There was no problem on 15.04, or on 15.10 up until the beta of early September. My desktop PC and my laptop both operate the Evolution addressbook online just fine. Both are up to date.
A new installation on this computer as at the release date for Wily shows the problem. I have set the online account to allow Evolution to access online data. When I try to set Evolution up exactly as on the two previous installations, I cannot do so without allowing it to add the passwords to my personal keyring. If I uncheck the 'add password to keyring' box, Evolution cannot be set up with any account data.
I have spent a number of hours trying to find a workaround, bu so far with no success. I assume this is an Evolution problem, but obviously Seahorse is invoked.
ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: evolution 3.16.5-1ubuntu3
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Oct 29 09:35:15 2015
InstallationDate: Installed on 2015-10-22 (6 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20151014)
SourcePackage: evolution
UpgradeStatus: No upgrade log present (probably fresh install)
A bit more information I ought to have included. The only difference between the two previous installations is the password/seahorse password requirement. In the new installation, Evolution is unable to access the Google account even though this is made available to Evolution in 'Online Accounts'. All settings in Online Accounts, and in Evolution are identical to those in the earlier installations.
I set up a second administrator account on this computer, and repeated the Evolution and Online Accounts setup procedure, so the problem seems to be repeatable.