If you are getting this error in XPS Ship when using WooCommerce this is likely caused by a security feature of the iThemes security plugin. **If you are not running iThemes, the setting is likely found in the Apache configuration and may need to be addressed there. Follow the steps below to resolve the issue.
Log into your Wordpress admin account.
Select Security –> Settings –> System Tweaks –>Configure Settings.
Uncheck the “Filter Long URL Strings” checkbox. The checkbox is about halfway down the page.
Return to XPS Ship and refresh your browser. The error will disappear after the system has refreshed.