Data1.cab Error

I've spent the last couple hours trying to install the game on my friends computer (via TeamViewer) and we have had zero luck.

For a while, it kept saying the files were corrupt, and we had to keep redownloading them using different browsers but were finally able to get the installer to work. DirectX and POL installed fine (and I was able to update POL). But every time we try to install FFXI, it keeps bugging out and giving the same error.

We have tried everything we can possibly think of. He's running W11 (same as me and I had no issues at all). We turned off his AV, firewall, Defender, ran in compatibility mode for different versions of Windows, run as admin. There have been a lot of windows extension changes that we tried, update every driver I can find, every single possible solution and nothing has worked. SE just said to buy a new copy of the game, which we've tried downloading from numerous sources and none of them have fixed the issue.

This is the closest we have gotten, even after deleting and uninstalling everything and starting fresh, numerous times.

Install from a different drive to discount drive error.

A memory check is also a good idea. Sounds like corrupted data, either drive or memory.

delete all the files and just tell them to download them and install, it's possibly that you doing it in the way you are that's causing issues (teamviewer).

The reason I was using Teamviewer to install it is because he was having issues installing it on his own. I even tried using Teamviewer to send him the files after I downloaded them, because his kept saying they were corrupt.

He actually just bought a brand new HDD thinking that his was buggered. Same issue persists.

Your image isn't visible (yet), but a very similar sounding thread from 2015 was fixed with this post:

https://www.ffxiah.com/forum/topic/45791/cant-install-ffxi/2/#2823101

If that doesn't do it but your error message is similar, there's a few other good ideas in that thread.

https://www.reddit.com/r/ffxi/comments/8fmdyf/returning_player_needs_tech_help/

Apparently this happens if you don't properly uninstall the game at some point.

We were trying to install it on a fresh Windows install, because we thought the old version of Windows might've been corrupted.

I'll send that to my friend and see if that helps him.

unsure if the same issue, but a few years ago, i had to do an uninstall, and after trying to re install, my pol would install fine, but FFXI would error out, my tech guy couldnt make heads or tails of it at the time, but instead we opted to try an older version of playonline. It worked and installed fine with that (Alot more update items, but no sudden errors and disconnects) I wouldnt know where to find that now but he had an older installer folder on his fathers pc.

I think I have an old disk somewhere, back when they sold the base game for super cheap. I might try locating that and see if that works.

Simply the files are corrupt.

Whether or not that is caused by a bad download (probably didn't let it finish or compare the hash) or a hardware issue, but most likely the former.

The files weren't corrupt, turns out the RAM was installed incorrectly and after removing and reinstalling it, the CMOS rewrote itself and the issue was fixed. It's an HP prefab computer and they didn't build it correctly (turns out there was an SSD that wasn't even connected). Once the computer started up, we tried the exact same files that were showing up as "corrupted" and the game installed without any issues.

For as many times as we downloaded the game (including me sending the files to him from my computer, that I used to install the game without any issues), I knew the files weren't actually corrupted. I just couldn't figure out what was causing the computer to think that they were.

lolwut...