This should not be suppressed:
if ($dir = @dir(DIR_FS_ADMIN . 'includes/boxes')) {
Better:
if ($dir = dir(DIR_FS_ADMIN . 'includes/boxes')) {
Reason:
DIR_FS_DOCUMENT_ROOT was wrong, but I did not found this reason directly because of the suppressed error. This is the bug because DIR_FS_DOCUMENT_ROOT was wrong:
https://github.com/osCommerce/oscommerce2/issues/600
Regarding v2.3.4
This should not be suppressed:
if ($dir = @dir(DIR_FS_ADMIN . 'includes/boxes')) {
Better:
if ($dir = dir(DIR_FS_ADMIN . 'includes/boxes')) {
Reason: DIR_FS_DOCUMENT_ROOT was wrong, but I did not found this reason directly because of the suppressed error. This is the bug because DIR_FS_DOCUMENT_ROOT was wrong: https://github.com/osCommerce/oscommerce2/issues/600