Toolbar buttons suddenly disabled

[AC]

Ok, running 2.6.3, no major issues until now.  I usually leave it up and
running so I can avoid the startup delay and add entries as needed.
However, very recently (within the past couple weeks) all the toolbar
buttons would suddenly gray out and become disabled.  I was able to
switch from account to account using the tabs but I could not enter
transactions, open splits, or do anything else.  It looked like the
identical menu options had become disabled, too.

I have to shut down and restart GC to bring back the buttons.

No recent changes to the computer (in fact the computer hasn't been
rebooted in several months).