[Evolution] Evolution stopped working altogether

[van snyder <van snyder sbcglobal net>]

I got a message about security updates for Debian 10 Buster. They were mostly about WebKitGTK. Last week, when I started having trouble with gmail and OAuth2, one possibility remarked was that WebKitGTK might be causing the problem. So I eagerly accepted the updates.

I logged out and logged in again. Evolution would not forward messages.

So I rebooted.

Now, when I load evolution from the KDE task bar nothing happens.

When I load from a terminal command line, it says

 terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc

(evolution-alarm-notify:4529): GLib-GIO-WARNING **: 19:48:40.765: Your application did not unregister from D-Bus before destruction. Consider using g_application_run().

and the graphic interface is not launched.

What should I do?