- make a copy of the file (for backup)
- open the file with Libre Office (with Neo Office on Mac)
- click on "Edit" then "Find and replace"
- a window appears
- in the "Search" field, type: \n
- in the field "Replace with", type the character Space
- click on the "More options" button
- tick the box "Regular expressions".
- at the bottom, in "Search in", select "Values"
- at the top, click on "Replace All"
My import file contains line breaks in the cells
To remove the line breaks inside the cells of your import file: