Error upload files lib/pkp/classes/core/String.inc.php

hello all when I try to upload files gives me the error; ojs2 has produced an error message: WARNING: escapeshellarg () you has-been disabled for security Reasons In file
lib / pkp / classes / core / String.inc.php At line 396.
ojs use 2.4.6 can help me?
thank you

Your administrator or host has disabled some of PHP’s features which enable it to execute commands on the server. Check with your provider to see if they can be enabled (specifically escapeshellarg().

Alternately, check if they can help get the PHP mime_content_type() function working (or working better). The functioning of mime_content_type() may depend on the correct setting of mime_database_path in config.inc.php. If mime_content_type() returns a valid result for the file, the call to escapeshellarg() is bypassed.

thanks for the reply, my hosting says they have not changed anything, have not disabled the function or anything, everything worked fine until two days ago ago.
mime_content_type are fine. What more could I do?
thank you!

If nothing has changed, the logical assumption is that whatever file you are uploading in particular is not being identified correctly via mime_content_type(). Is it a new kind of file?

Can you manually execute a mime_content_type() check on the file via the server and report the results?