If you're undergoing a significant version change in the product or system your users work with, run the current and new versions in parallel for a while.

Default to the current, offering low risk, bite-size ways to dip into and explore the new version.

Be clear about the date at which the user will be defaulted to the new version.

Provide ample time for incremental exploration (measured in months, subject to the size of the change). Once the user has been defaulted to the new, maintain provision of access to the old for a time, to increase certainty further.

Finally, provide a clear date by which the old will no longer be accessed.

What significant systematic changes are you anticipating for your users? Where can you reassure them with a smooth migration process that reduces stress and, ideally, reinforces the value of the new?