My import file contains line breaks in the cells

To remove the line breaks inside the cells of your import file:

• 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"