@tcnet As @kixe stated the "parseUserAgentString.php" is outdated and contains some bugs.
One of our clients recently saw PHP notices coming from this file for Apple users using Safari browser. Apparently the Major & minor version were set but not the build, as such $t[2] was undefined.
We fixed it by an extra isset().
Original:
$browserVersion = $t[0] . "." . $t[1] . $t[2];
Fix:
$browserVersion = $t[0] . "." . $t[1] .(isset($t[2]) ? $t[2] : '');