Using the payment processor PayPal_Standard on a fresh install of CiviCRM Version 4.7.29 (with Wordpress 4.9.1 on Centos 7.4) breaks all contribution pages where PayPal is enabled. The result is a blank page. In the Apache error log there is:

PHP Fatal error: require_once(): Failed opening required 'CRM/Core/.php' (include_path='.:/somedir/wp-content/plugins/civicrm/civicrm:/somedir/wp-content/plugins/civicrm/civicrm/packages:/somedir/wp-content/plugins/civicrm/civicrm/vendor/tecnickcom:/somedir/wp-content/plugins/civicrm/civicrm/vendor/phpseclib/phpseclib/phpseclib:/somedir/wp-content/plugins/civicrm/civicrm/vendor/pear/pear_exception:/somedir/wp-content/plugins/civicrm/civicrm/vendor/pear/auth_sasl:/somedir/wp-content/plugins/civicrm/civicrm/vendor/pear/net_socket:/somedir/wp-content/plugins/civicrm/civicrm/vendor/pear/net_smtp:/somedir/wp-content/plugins/civicrm/civicrm/ve in /somedir/wp-content/plugins/civicrm/civicrm/Civi/Payment/System.php on line 59, referer: https://someurl/civicrm/?page=CiviCRM&q=civicrm/contribute/transact&reset=1&id=1

When disabling PayPal (= pay later) the contribution pages work fine.

Any ideas what might be going wrong here?

2 Answers 2


You're experiencing the bug documented at CRM-21595. You will need to apply the patch or wait for CiviCRM 4.7.30.

Most people won't experience this bug if they disable "Pay Later" as an option.

  • Phew, that worked for me too
    – Jon-man
    Jan 24, 2018 at 10:48
  • Weehaww! Worked for me. No "Pay Later" on my configs, but still got the bug. Applied patch and everything is back to normal! Thanks, Jon! Feb 1, 2018 at 5:12

You can install the rc for 4.7.30 which is what I recommend - it's at download.civicrm.org/latest

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