When I open iWeb site, which was working fine last night, I get a dialog saying files are missing. Six files are missing; 1 png, 2 jpg and 3 tiff. To the best of my knowledge there are no tiff files in the domain and a search of my hard drive doesn't find them. Please tell me what's going on. I've been looking for an answer all day.

Thank you,
Hozey

That's probably a problem which affects only you so I don't know what's going on but if you'd have a backup of the domain from before you got the message I'd try to restore it.
If you don't have a backup it probably affects a page you edited the last time before getting the message so deleting that page and rebuilding may help.
But it may also affect the application and not the site. This could be tried by opening another domain file. If problem persists problem is the application if not problem is the domain file. If it's the application you may reinstall it.
Otherwise just ignore dialog.

Regards,
Cédric

Can't ignore dialog. When continue is clicked my home page shows everything there but all items have Xs through them and there are x'ed out boxes running the width of the page from top to bottom and ? marks. See attachment. If I try to publish it gives me an unknown error. Thanks,
Hozey

Wow, you may want to try to reinstall iWeb then. Looks like some theme files are missing. Or you may try my other tip opening another Domain file first.

I've had the same problem a few times, and what I usually have to do is delete the website files and folders through the hosting file manager, go into iWeb, drop down the file menu, and hit "publish entire site". I think I've had to do that twice before. If this doesn't' work for you, do what Cedric says.