Solutions for "Unknown error occured" when publishing in iWeb

Question

Many complaints where written on the forums about this annoying *"Unknown error occurred"* bug, while publishing in iWeb.
Until now, nobody could actually find the problem, but in most cases the problem is not a network connection, but an iWeb bug, that occurs during html files creation process.
I'm using iWeb a lot and through my work found several different solutions, that worked for me and for many other users. Try them all out, before going desperate and rebuilding the site from scratch:
1. Try closing and reopening iWeb (do it in all other steps between operations).
2. Try to publish the site Locally. If it works, try publishing to the server again.
3. Try publishing the ENTIRE site, first Locally, then to the server (File>Publish Entire Site). This operation forces iWeb to rebuild all the files from skratch.
4. Try closing iWeb and deleting the User/Library/Preferences/com.apple.iweb.plist preferences file. iWeb will create a new one again next time it opens (don't worry, you will only lose iWeb preferences, but not your website)
5. If publishing locally worked, but online didn't, then upload the locally published site folder to your server manually using any FTP client.
6. If nothing works, try reinstalling iWeb. Before doing that, back-up your project file, which is located at +User/Library/Application Support/iWeb+ to some other location.
Also, as an advice, avoid using non web-safe names in your files and web pages. I.e. - don't use spaces and Capital letters, this may cause problems. For example, instead of naming a file: "Nice picture.jpg", name it: "nice_picture.jpg"
Post more solutions, if you have them.

Answer 1

Try signing out of the app (Store menu,) quitting the app, restarting the app and signing back in.