With a recent update (I'm on 14.04 LTS), Wine suddenly stopped working. It turns out this has already been reported at WineHQ where the related bugreports are linked.
The advice there is to downgrade the kernel while awaiting the fix, referring users back to their distros on advice for doing the "downgrade". There are quite a few Q&As about this, but the 14.04 specific ones don't appear to meet this need. (And the "similar questions" in the sidebar are often quite old.)
How should the kernel be safely downgraded while not prohibiting automatic updates (to catch the fix which is surely coming soon!)?
The problematic update in my case appears to be this one:
2015-07-28 14:08:18 upgrade linux-libc-dev:amd64 3.13.0-58.97 3.13.0-59.98