It's a square issue I think. Something to do with the shitty patch server they're using.will that work on PC as well?
This is absurd issue Sony, fix this shit. Google searches show this has been going on for years.
If it doesn't work try the google dns server posted here.
And if that one doesn't work and you're on pc then you should be able to get around the issue by using a vpn like Mudfish. It'll cost you a few bucks though.I had this issue as well, for DNS I used 4.2.2.2 and as a secondary I used 4.2.2.3. I also had my MTU at 1450. The download was slow but it was the only solution that didn't give me errors.
Finding solutions for this shit was torture, and I'm sure you've probably tried just as much shit as I did. Hopefully it works for you so you can at least play, because the game is a ton of fun. Just a matter of getting to the point to actually play it.
This is not an issue I have presently but is a record of a solution that worked for me, today, for future searchers. This post will hopefully save time for anyone that has this problem now or in the future.
I was unable to download patch h2014.05.27.0000.0000g. The error message was "Unable to download patch files. [30413] [25008] [20495]". The error appeared at random points near 470MB. I succeeded in downloading 6 patch files before this.
I tried the following steps: Close all background applications. Disable all security software. Clear cache. Delete download folder in My Games. Uninstall FFXIV and try again.
None of these attempts worked. What DID work was retrying the download through a free VPN. I downloaded just this one file, canceled on the next one to switch off the VPN, and resumed downloading normally. I am not done patching, but I have encountered no issues since.
This is, as others have suggested, either a routing or port issue. By using a VPN, a different route is used and (I believe) port forwarding becomes a non-issue.
Other things that worked for others, which I did not try: Waiting and trying again later. Switching from Wireless to Wired.
Some people have contacted tech support, but I have found no remarks of positive outcomes. This may simply be a failure to return to the conversation once their issue was resolved.
https://www.reddit.com/r/ffxiv/comments/4j7vaj/resolved_unable_to_download_patch_files/