I noticed this bug on 5.23 beta1 and dmaster, and somehow I don't think it's specific to 5.23, but I'm not seeing it elsewhere:

• Change the CiviCRM language to another language (ex: en_UK) link
• Use the default phpgettext, not native gettext
• Go to Find Contacts, then click Find. (i.e. search all, doesn't matter)

Resulting fatal: Select_string only accepts integers: 1

Relevant backtrace bit:

      array(6) {
        ["file"]=>
        string(79) "/var/aegir/platforms/civicrm-d7/web/sites/all/modules/civicrm/CRM/Core/I18n.php"
        ["line"]=>
        int(451)
        ["function"]=>
        string(8) "ngettext"
        ["class"]=>
        string(14) "gettext_reader"
        ["type"]=>
        string(2) "->"
        ["args"]=>
        array(3) {
          [0]=>
          string(14) "%count Contact"
          [1]=>
          string(15) "%count Contacts"
          [2]=>
          string(3) "241"
        }
      }

This is from a ts call in ResultTasks.tpl. Oddly, that file has not changed in many years.

Enabling Native gettext (which I recommend) mitigates this problem, but obviously not a good core fix.

Can someome confirm if it is a regression?