Actually you are probably running into the issue of your virtual memory running out and you get an out of memory error.
There is no leak. I need that to get understood.
There IS a lot of memory use however, and yes, its messy. And if you have a larger amount of video memory (in your case, 24GB) it will use even more virtual memory as a result.
Fortunately, for some there is one working solution for memory problems. If you haven’t read it on a number of other threads already that is.
Go here, try using this solution:
-Diablo IV has run out of memory - #103 by DTMAce-1687
Otherwise, pull the latest Fenris log, copy the contents, use pastbin.com to provide us a copy of the log to review and find the issue if it can be located.