XFtoWP 1.5 Upgrade Guide
To upgrade websites running XFtoWP 1.4.x to the now stable XFtoWP 1.5 release, follow this guide to import existing site data for full support for the plugin’s powerful new features and a more streamlined logging system.
Note: If you are installing XFtoWP for the first time or have not synced any threads and users, this guide does not apply to you.
After updating the plugin from the auto updater or installing XFtoWP 1.5 yourself, you will be prompted with an important upgrade notice in your WordPress dashboard. Please follow the link to go to the updater screen.

If your site has any users or threads connected, you will need to perform a simple migration of their sync logs. It is important to keep your sync logs up to date as it keeps your data better organized and prevents unwanted syncing mix-ups.
Luckily, XFtoWP 1.5 makes this migration easy with its very own Bulk Actions tool:

Follow the prompts to update both users and threads logs, and the plugin will continue full operations and ready for you to try out the many new features introduced in XFtoWP 1.5!