I have a problem uploading files to my main webpress site (e.g. www.main) and all the other pages that live in it (e.g. www.main/anotherpage). I know there is a method to set a temp folder like

define( 'WP_TEMP_DIR', dirname(__FILE__) . '/wp-content/temp/' );

but I have already put this line in the wp-config.php file but I did have any success. Also I have already changed all permissions to the folders using (maybe is better to use 775, but I wanted to check if that could help)

sudo chmod 777 /wp-content/temp

But I did not have any success either. I am not really sure where this problem came from; maybe after a plugin update. I am pretty new in wordpress and I'm not sure how to proceed. I hope someone can give a hint with this problem. Thanks in advance.