How I kept iWeb alive on El Capitan another day
I just discovered problems with iWeb after upgrading from Yosemite. The two killer ones were blank text boxes and failure to publish to my sftp:// site.
Before resigning myself to a huge amount of work with a new editor, I tried simply publishing to a local folder and use FileZilla to manually update my site. Your mileage may vary but, as the coder says: "Works on my machine!".
Adrian
MacBook (Retina, 12-inch, Early 2015), OS X El Capitan (10.11.2)