I just deployed a Tiki Wiki 16.2 instance on a Ubuntu 14.04 server. And then I was trying to add the LDAP authentication to it but the user got redirected to a blank page or error one saying that it could not be handled. It turns out that there is a bug in the PEAR module.
Luckily, I could fix the bug by editing vendor_extra/pear/PEAR.php, renamed the following functions:
function __construct($error_class = null) -> function PEAR($error_class = null)
function __construct($message = 'unknown error', $code = null, -> function PEAR_Error($message = 'unknown error', $code = null,
Remember, this is just a workaround. The fix was added in the daily build.