Yes, I saw that on my website once I upgraded to v1.5.6b. The issue is a missing
/ in /includes/init_includes/init_ipn_postcfg.php on line 22. You'll need to change
Code:
require(zen_get_file_directory(DIR_FS_CATALOG . DIR_WS_LANGUAGES . $_SESSION['language'], 'checkout_process.php', 'false'));
to
Code:
require(zen_get_file_directory(DIR_FS_CATALOG . DIR_WS_LANGUAGES . $_SESSION['language'], '/checkout_process.php', 'false'));
I'll be submitting a PR to Zen Cart's 1.5.7 branch to provide future correction.
See this (
https://github.com/zencart/zencart/pull/2442) PR for additional information.