When downloading a really large file of several gigabytes via browser, you may encounter an Out of HTML5 Storage space error.
This error has nothing to do with free space on your drive. It is caused by fantastic skills of the browser developers, in this case – the all-around perfect Google Chrome. It limits the maximum storage for internal functions, however, has it unlimited for plugins. Thus, just install the correct add-on to download from the required resource, in this case, Mega. Restart the PC, and the large download should complete.