When I launch the installation of Xoops I can see Array in the lists containing the language or the type of database to use.
If you are using php 4.3.10 and the Zend Optimiser, ask to your provider to upgrade Zend Optimiser to its last version.
This Q&A was found on XOOPS Web Application System : https://xoops.org/modules/smartfaq/faq.php?faqid=349