QuickForm Error w/ CiviCRM 5.33.0

Question

Right after the update to CiviCRM 5.33.0, many pages (as civicrm/case/add or civicrm/mailing/browse/scheduled?) throws the following error - QuickForm Error: the rule does not exist as a registered rule Is there a quick fix for this QuickForm ?

There is some details in the logs w/ a xssString :

[debug] $backTrace = #0 /PATH/vendor/civicrm/civicrm-core/CRM/Core/Error.php(205): CRM_Core_Error::backtrace("backTrace", TRUE)

#1 /PATH/vendor/pear/pear-core-minimal/src/PEAR.php(944): CRM_Core_Error::handle(Object(HTML_QuickForm_Error)) 
#2 /PATH/vendor/civicrm/civicrm-core/packages/HTML/QuickForm.php(2107): PEAR_Error->__construct("the rule does not exist as a registered rule", -2, 16, (Array:2), "Rule 'xssString' is not registered in HTML_QuickForm::addRule()")
#3 /PATH/vendor/pear/pear-core-minimal/src/PEAR.php(575): HTML_QuickForm_Error->__construct(-2, 16, (Array:2), "Rule 'xssString' is not registered in HTML_QuickForm::addRule()")
#4 /PATH/vendor/pear/pear-core-minimal/src/PEAR.php(236): PEAR::_raiseError(NULL, NULL, -2, 16, (Array:2), "Rule 'xssString' is not registered in HTML_QuickForm::addRule()", "HTML_QuickForm_Error", TRUE)
#5 /PATH/vendor/civicrm/civicrm-core/packages/HTML/QuickForm.php(1109): PEAR::__callStatic("raiseError", (Array:7))
#6 /PATH/vendor/civicrm/civicrm-core/packages/HTML/QuickForm.php(689): HTML_QuickForm->addRule("title", "Illegal characters in input (potential scripting attack)", "xssString")

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Answer 1

@ichi that rule shouldn't be existing anymore because it was removed in 5.33 https://github.com/civicrm/civicrm-packages/commit/148eb5483caa1059d031f11aaf32b391bead1c66 I would suggest applying that patch onto your system and that should fix the problem

Answer 2

This error may occur, If you have added any formRule in a custom form in any of your extension(s) .

For example:

$this->addFormRule(array('CRM_Myextension_Form_Myform', 'myFormRule'));

If you have any line(s) like above in your custom form then you need to change that as below:

$this->addFormRule(array($this, 'formRule'));