I'm using Joomla 3.7.5 and CiviCRM version 4.7.12. I access to "CiviCRM » Administer » System settings » Extensions » Add new" to install CiviHR extension but CiviHR not in the native list. So I do it manually, I downloaded CiviHR and upload to civicrm directory. When I install it, I got the error. The first, I click "install" And I got the error Do you have any suggest for me to fix this? Thanks you very much.
It sounds like CiviHR is still using the php-mysql extension not php-mysqli. You can try installing php-mysql, or asking your hosting provider to do it, but if they're running a fairly recent server they may not be able to.