I found something in an older thread
changing
$PhpUploader_FSEncoding="ISO-8859-1//TRANSLIT";
for
$PhpUploader_FSEncoding="ISO-8859-6//TRANSLIT";
in the very first line of the file include_phpuploader.php
does the trick.
Changing for
$PhpUploader_FSEncoding="utf-8";
seems to work too. Is there any harm to use this more universal encoding?
many thanks