Try saving it as a Outline/RTF.
To do so, click File > Save As.
Under Save as type, click on the dropdown and scroll down to the bottom.
Select Outline/RTF (*.rtf).
Click Save.
Now, open the rtf file in Microsoft Word and see if it works this time round.
Take note that only the text entered in placeholders will appear. If you
entered text in a textbox that you have created, it will not be shown in the
outline.