Invalid argument supplied for foreach() in functions_prefix.php on line 133

[postcd]

Hello,

anyone also found this PHP error in the vbulletin 4.x error log?

Invalid argument supplied for foreach() in /includes/functions_prefix.php on line 133

I am having 4.2.5 and PHP 5.6.40

$ grep foreach functions_prefix.php

        foreach ($restrictions AS $usergroup)
                foreach ($prefixsets AS $prefixsetid => $prefixes)
                        foreach ($prefixes AS $prefixid => $prefix)
                foreach ($valid_prefix_sets AS $prefixset)
                        foreach ($prefixset AS $prefixid => $prefix)

I checked the StackOverflow topic "Invalid argument supplied for foreach()" but not sure how i should adjust above foreach lines. Any idea please?

One answer was:

foreach ((array) $items as $item) {
 // ...
 }

So i tried replacing:
foreach ($
by:
foreach ((array) $
resulting in:
$ grep foreach functions_prefix.php

        foreach ((array) $restrictions AS $usergroup)
                foreach ((array) $prefixsets AS $prefixsetid => $prefixes)
                        foreach ((array) $prefixes AS $prefixid => $prefix)
                foreach ((array) $valid_prefix_sets AS $prefixset)
                        foreach ((array) $prefixset AS $prefixid => $prefix)

is that right, or how better do it please?