When using Beta5's escapeHtml or escapeHtmlAttr helpers, the preg_match() function fails with the following error message.

preg_match(): Compilation failed: unknown option bit(s) set at offset 0 in /var/www/html/vendor/zendframework/zendframework/library/Zend/Escaper/Escaper.php on line 349

Line 349: } elseif (preg_match('/^./su', $string) == 1) {

The server is running with PCRE version 7.8 with UTF-8 & Unicode support on.

PCRE version 7.8 2008-09-05
Compiled with
  UTF-8 support
  Unicode properties support
  Newline sequence is LF
  \R matches all Unicode newlines
  Internal link size = 2
  POSIX malloc threshold = 10
  Default match limit = 10000000
  Default recursion depth limit = 10000000
  Match recursion uses stack