Thread:Project:Support desk/Cannot edit pages/reply (4)

OK, in fact it looks like it is exactly this error: https://bugzilla.wikimedia.org/show_bug.cgi?id=58213 The fix will be part of MediaWiki 1.22.2. It will require at least PCRE version 7.2; MediaWiki will no longer be installable/updatable with older versions.

PHP 5.4.14 by default includes PCRE 8.32 and according to the bug report, the problem should only arise with versions of PCRE older than 7.2, but not with 8.32. Since you have the problem anyway, I guess that your PHP version is compiled with an older version of PCRE. You have to use a newer version of PCRE! Also see Manual:Errors_and_symptoms/PCRE.