html - unsupported media type error?

Hi all, and Happy New Year!

I am using namazu for Windows and trying to construct an index using mknmz.

However, the program returns the following error for every html page in the
directory:

1/9 - /c|/Perl/t3/thrd24.html Unsupported media type (text/html;
x-type=mhonarc)
 skipped.

Could anyone provide any direction as to where I am going wrong here?

Many thanks in advance

James