Fonts are not contained within an InDesign document but certainly are referenced by an InDesign document.
The OS/2 table referenced by the error message refers to a required component of either TrueType, OpenType CFF, or OpenType TrueType fonts. It contains critically-important information about the font required to properly format, display, and print text using that font. You can find specifications for the OS/2 table at https://docs.microsoft.com/en-us/typography/opentype/spec/os2.
Quite frankly, I have never heard of a situation where InDesign (actually, the underlying font engine of same) yielded such a diagnostic of “missing the required OS/2 table.” It would be very hard to imagine either Windows or MacOS allowing installtion of such a damaged font.
My only advice would be to uninstall the font in question completely from the system, reboot the system, and then reinstall the font from a known working copy.
Let us know if that resolves the problem (and also perhaps, exactly what font was causing this problem).
- Dov