Php functions imap_sort and imap_search have encoding parameter, its null by default, but if it’s set in code to null the error occupies:
Uncaught TypeError: imap_sort() expects parameter 6 to be string, null
code: \imap_sort($resource, $sortCriteria, $descending ? 1 : 0, \SE_UID, $query, null);
How to set default value for encoding exactly (So, I can't just remove this parameter) ?