The default VizieR server used by Guide has just had its URL
changed. I'll revise Guide to point to the new address. In the
meantime, there's a reasonably simple fix: edit 'guide.dat' and
cut-and-paste this line into it:
and restart Guide. You'll again able to get data from VizieR.
Alternatively, you can run Guide and hit Alt-J, and cut-and-paste
the above line into the resulting dialog box. This will have
basically the same effect.
There are a slew of VizieR mirrors, any of which can be used
in the VIZIER= line: