Here's the error when using 
Add-on Installer.
Zend_Filter_Exception: Given file is no zip archive - library/Zend/Filter/Compress/Zip.php:233
Generated By: 
Isabel, Today at 7:04 AM
Stack Trace
#0 /home5/eqaddict/public_html/testingtesting/library/Zend/Filter/Decompress.php(47): Zend_Filter_Compress_Zip->decompress('/var/tmp/phpt9F...')
#1 /home5/eqaddict/public_html/testingtesting/library/AddOnInstaller/Model/AddOn.php(29): Zend_Filter_Decompress->filter('/var/tmp/phpt9F...')
#2 /home5/eqaddict/public_html/testingtesting/library/AddOnInstaller/ControllerAdmin/AddOn.php(57): AddOnInstaller_Model_AddOn->extractZip('/var/tmp/phpt9F...')
#3 /home5/eqaddict/public_html/testingtesting/library/XenForo/FrontController.php(337): AddOnInstaller_ControllerAdmin_AddOn->actionInstallUpgrade()
#4 /home5/eqaddict/public_html/testingtesting/library/XenForo/FrontController.php(134): XenForo_FrontController->dispatch(Object(XenForo_RouteMatch))
#5 /home5/eqaddict/public_html/testingtesting/admin.php(13): XenForo_FrontController->run()
#6 {main}
Request State
array(3) {
  ["url"] => string(71) "
http://eqaddiction.com/testingtesting/admin.php?add-ons/install-upgrade"
  ["_GET"] => array(1) {
    ["add-ons/install-upgrade"] => string(0) ""
  }
  ["_POST"] => array(6) {
    ["resource_url"] => string(0) ""
    ["login"] => string(0) ""
    ["password"] => string(8) "********"
    ["server_file_oldskool"] => string(0) ""
    ["_xfConfirm"] => string(1) "1"
    ["_xfToken"] => string(8) "********"
  }
}