The problem disappears if I omit the option
pagebackref=true in the hyperref praeamble.
With the option, the error message occurs, but
a pdf is produced in the lyx\temp folder. It can be
viewed by defining the new format (Edit->
Preferences->File Formats->New) with
Format: pdf4
GUI name: PDF (view)
Extension: pdf
Viewer: pdfviewer
and definining the new viewer by placing a file named
pdfviewer.cmd containing
kill -c AdobeAcrobat
del viewer.pdf
copy %~dpn1.pdf %~dp1\viewer.pdf
START /max AcroRd32.exe %~dp1\viewer.pdf
exit
into the lyx\bin directory.
The first line in pdfviewer.cmd uses
the kill utility from
http://21st-century.net/Pub/WINNT/Utilities/kill.zip
to kill any existing Acrobat window.
It can be omitted, but in this case
all Acrobat windows must be closed manually
before invoking the lyx command
buffer-view pdf4
from the mini-buffer or from the toolbar
(if placed on the toolbar by adding
Icon "buffer-view pdf4"
under the toolbar heading in the .ui file).
HTH - in (unlikely but annoying) case that
somebody runs into a similar problem as I did.
Ekkehart
