Switch to the older version of InDesign. Choose File > Open and navigate to the IDML file you just exported. When you open an IDML file, InDesign will automatically convert it into a native .indd file for that version, allowing you to edit and save it normally [1†L4-L8][12†L11-L13].
However, for 99% of users, the built-in method described above is the safest and most reliable route. how to convert indesign file to older version
Always review these five specific elements after down-saving a file: 1. Text Reflow and Overset Text Switch to the older version of InDesign
The primary way to "downsave" a file is through the export function within InDesign itself. for 99% of users