The JParameter/JRegistry strict standards error affected Joomla 1.5 and 2.5, which have been end-of-life since 2012 and 2014 respectively. This error occurred when running old Joomla code on PHP 5.4+ due to stricter object inheritance rules.
If you are still running Joomla 1.5 or 2.5, you should upgrade immediately - these versions have known security vulnerabilities and are no longer receiving patches. The current Joomla version is available at joomla.org.
Running end-of-life CMS software is a major security risk. If your Joomla site shows this error, it is running a version that is over 10 years out of date. Consider upgrading to the latest Joomla or migrating to WordPress. If your site has been compromised, see our malware remediation guide for general cleanup steps.
This issue affected Joomla 1.5/2.5 (end-of-life 2012/2014). This article is preserved for reference only.
