XOOPS returns a fatal error after first use of the Protector Module (e.g. when setting Preferences): Error : TypeError: fwrite(): Argument #1 ($stream) must be of type resource, bool given This is due to incorrect permissions on the following file: /var/local/lib/xoops/data/protector/configcachea07794 Which can be corrected by setting Ownership of file and directory to root:www-data and Permissions to 775 and 664 respectively.