As a seasoned Microsoft Word specialist with over a decade of experience helping users optimize their documents, I know compatibility mode can limit advanced features. Designed for cross-version collaboration, it restricts newer formatting in older Word versions. Here's how to disable it safely across editions, including Office 365.
Disabling compatibility mode lets you fully leverage modern features without risking document issues. Follow these proven steps:
This sets .docx as default, turning off compatibility mode for future saves and ensuring seamless work with the latest formats.
For Office 365 users, try this alternative:

In the Compatibility Checker, uncheck "Check compatibility when saving documents."

Access it via File > Options. This central hub lets you customize settings, UI, branding, and startup preferences for optimal productivity.
Grayed-out options often mean your Office isn't activated. Check via File > Account. If inactive, sign in and activate your subscription for full access.