Mail preferences pane problem in Mac OS

I found this procedure that was a solution for me:

• Quit the Mail application if it is open.

• Select Finder in the Dock.

• Navigate to "/Library/Containers/com.apple.mail/Data/Library/Preferences" in the finder ( hold down the “option” key while viewing the “Go” menu for Finder to find the Library folder ).

• Look for the file "com.apple.mail.plist" in the folder.

• Click and drag the file into the trash icon on your desktop ( or right-click and select “Move to Trash” ).

• Start Mail. You do not need to restart the Mac.

When I subsequently selected preferences, the preferences pane opened correctly — with all menus and content.

Sorry, I didn’t think to take a screenshot at the time the problem was occurring. My research on Apple community discussions showed a post with a similar problem but in High Sierra. I subsequently searched the web and found the procedure I describe below.

Also, all the previously listed solutions in that thread ( https://discussions.apple.com/thread/8154362 ), which I tried, did not work — I’m thinking they are perhaps unnecessary in this situation.