I just came across this problem myself. I could download any file under 6 MB in size, but it would time out and blow up for anything larger.
I found another thread, in which Ajeh told the poster to call their host and have them check for download size limitations.
However, there is another possible reason for this problem to occur.
As I stated, I had this problem as well, this very morning!! I also have free downloads on my site as well, and those files have no problems download, and at least one of those is larger than 12 MB.
I am on an IIS server, have Streaming set to true, redirect to false, and have my download folder outside my web root directory for security reasons.
So, I called my host and I explained the problem as fully as I could. He had me read off to him the URL from one of my problematic downloads, and it sparked something.
The URL for the download, when you click the download button, does not link to the file directly. Instead, it goes through the cart software. This means that it also goes through the PHP processor.
My host increased my PHP Maximum Execution Time in the PHP settings on the server, and I can now download my largest electronic file (48 MB) without any problems.
So, if you are having problems with downloads over a certain size, this could very well be a possible cause for that problem.



