OldToad said:

Try the following:

1 – close iWeb.
2 – delete the iWeb preference file, com.apple.iWeb.plist, that resides in your User/Library/Preferences folder.
3 – go to your User/Library/Caches/com.apple.iWeb folder and delete the contents.
4 – reboot.
5 – launch iWeb and see if there’s any improvement.

If that doesn’t help reinstall iWeb from the disk it came on. To do so you’ll have to first delete the current application and all files with “iWeb” in the file name with either a .PKG or .BOM extension that reside in the HD/Library/Receipts folder and from the /var/db/receipts/ folder,

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reinstall iWeb from the disk it came on and apply the latest updates.

via Apple – Support – Discussions – problem adding google map ….