Why I can't download big files in File Manager?

When downloading files from "shared/" folder you may encounter with too small value of PHP setting "memory_limit", it affects download since files from this folder are downloaded using PHP file "file.php".

Try to increase the setting value, one possibility is to add following line to the .htaccess file:

php_value memory_limit 128M

Remember that memory limit value must be always slightly larger than size of the file you are trying to download.