In the YetiShare log files you get the following error:
Out of memory (allocated x) (tried to allocate x bytes)
Downloads may also not be working correctly.
This is an issue with PHP not having access to enough memory to process the request. To fix it add this line at the end of your _config.inc.php file (in the script root folder):
In most instances this will fix the problem. If you still see the memory error message try increasing this value to 2048M to see if that also fixes it.