Recently ran into this issue on this very site so I did some digging.
If you get this error when you try to install extensions in a Joomla 1.5.x site on a server using MySQL 5,
check this out.
I had this when trying to install eXtplorer 2.1 witch was installed since I moved from another server using older MySQL. However I had some problems with it and needed a re-install. I uninstalled the older version and then downloaded eXtplorer 2.1 v2.1RC5. When I tried to install it I got an error stating something like this....
During some testing I found an issue with the latest PHP and osTicket. The one coding this puppy is not following php standards from what I understand so you need to disable logging for various errors. So in order to not get the dreaded PHP Strict Standards error in your logs make the following changes.
Read more: Fix for PHP Strict Standards issue with PHP 5.4.x