Newer versions of InDesign often have improved composition engines. Opening a file in an older version might cause text to wrap differently, potentially creating overset text.
This requires an internet connection and a valid Creative Cloud subscription. The "Middle Man" Strategy: Creative Cloud Libraries how to convert indesign file to older version free
When you try to open a document created in a newer version of CC, InDesign will often prompt you with a dialog box saying the file was created in a newer version. If you have an active Creative Cloud subscription, you can click (or "Sync"). InDesign will use Adobe’s cloud servers to convert the file to your current version automatically. Newer versions of InDesign often have improved composition