thumbpdf.pl is in scripts/thumbpdf, but in scripts.ini there is an additional perl in the path:
thumbpdf.pl
perl
thumbpdf=scripts/thumbpdf/perl/thumbpdf.pl
So thumbpdf.exe can't find the script and doesn't work.
Ulrike Fischer
Thank you, this will be fixed with the next update.
Thank you, this will be fixed with the next update.