I'm not ready to call this a bug in the forum software just yet. But if you have a file as an attachment ( or uploaded any other way, like with QSF Portal ) then you will not be able to download the file. Anything >= 8MB will be saved instantly to your drive as a 0 byte file. Regardless of the archive type. Can't test it with text, because I don't have any 8MB text files handy :P
I've checked my PHP configuration for anything that might shed some light on this, and I've come up blank. There don't appear to be any magic settings to set how large the gzip output can be, other than "output_buffering = 4096" which obviously isn't affecting it since I can download 7.9MB files just file.
Turning off gzip compression in the board settings does not help if your PHP configuration has "zlib.output_compression = On" set.
If output buffering is skipped entirely, then the file can be downloaded. I grabbed one which is 22MB and got it all, but the site was completely unusable while the file downloaded.
Is there a setting to raise the gzip buffer size? Some other PHP config option I'm missing? Or am I stuck with this?
I remember there being a PHP memory limit that was defaulted at 8 meg in your php.ini file, you can up this more to something like 15-20 meg safely. I've had this problem before with other PHP scripts before, never used what you're using though. Grep around for memory_limit, I can't remember the directive name in php.ini but I think that's what you're looking for. Oh, and you could probably grep for "8M" as well.
Yeah, I've already scoured through the php.ini file. For this site, we have the memory limit set to 25MB, as well as the post_max_size and file upload size. This isn't because of that. There seems to be some kind of unfortunate ceiling on how much data can be downloaded through zlib compression, because if it's completely disabled then download size is no longer a factor. It just blocks the site up until the download is done. Which obviously we can't have :P