In tools/preferences/miscellaneous I set C:\Program Files\Java\docs\index.html and ticked 'use this URL when generating project documentation' . This path correctly launches JDK documentation. However javadoc generation fails (netbeans is able to generate okay and bluej will then view these docs). Log error is
- Illegal package name: "Files\Java\docs\"
It appears that the javadoc link option path
has been split into two lines(CR+LF inbetween, as above, in the log file)
The error goes away on unticking 'use this url when generating project documentation'