You have the following error:

PHP message: PHP Fatal error: Declaration of MzPetitionsModule::serviceBrowseCategory($sUnitView = false, $bEmptyMessage = true, $bAjaxPaginate = true) must be compatible with BxBaseModGeneralModule::serviceBrowseCategory($sUnitView = false, $bEmptyMessage = true, $bAjaxPaginate = true, $aParams = []) in /.../modules/modzzz/petitions/classes/MzPetitionsModule.php on line 833"

Which means that Petitions module isn't compatible with UNA v.13.1.0-B2, please ask author of this module to update it as soon as possible, alternatively you can deactivate this module until it's fixed.