Open a Finder window. From the Finder menu bar click Go > Go to Folder
Type or copy paste the following:
Click Go then move the Cache.db file to the Trash.
Quit and relaunch Safari to test.
If that didn't help, copy and paste the following:
Click Go then move the com.apple.Safari.plist file to the Trash
Try resetting your home page.
Thank you: I guess this is the only way.
I tried that, but my Safari preferences window does not look like yours, and I think it's because I have Firefox set as my default. Where yours says "Safai opens with" mine says "New windows open with" and then I have a half dozen choices, not just two.
Thanks to all for your help.