Click the icon at the right end of the columns (see picture), Restore Column Order. If that doesn't restore the From column, choose another folder that displays the right columns, then click the icon, Apply columns to..., the original folder.

Thanks for help, much appreciated, but I can find no column with Restore Column Order listed as pictured on inbox nor anywhere else on TBird. I am going to give up on this as it is a complicated interface anyway and move to eM Client which is much simpler.

You mention you can see 'Subject' ,'Date', column headers but not a 'FROM'. So it would appear you just need to enable the 'FROM' column header or force a restore.

To the right of the 'Subject' ,'Date', column headers, there is a small icon. When you click on it you get a drop down list. Select 'From' in the list. Look at image below it will help explain visually.

To increase the size of the image, view in this forum question and click on image to enlarge.

Thank you v much! I didn't see that tiny icon! Problem solved.