By default, Hesk removes all characters from file names except for a-z, A-Z, 0-9, . _ -
This is done both for security reasons (to prevent any attempts to pass invalid or malicious file names to Hesk) and to avoid encoding-related issues (for example, if the file name is in a different encoding than UTF-8, such as from email headers).
If you want to allow Cyrillic and other non-latin characters in file names, you will need to remove or comment out this line in inc/posting_functions.inc.php:
Code: Select all
$filename = preg_replace('/[^A-Za-z0-9\.\-_]/','', $filename);