A system error has occurred: 0 unknown on launcher boot

I'm seeing similiar issues from the Europe servers being posted in a sticky. I'm in the United States, so posting separately but with same requested info.

"You don't have permission to access this resource."

"Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request."

I have tried disabling firewalls and all other shields, and ensuring ffxiv is properly added to firewall exceptions after reenabling them.

Virus Scanning software: Avast
ISP: Spectrum
No tickets opened with them
United States
9/12/25 11:30AM EST first noticed
Constant repeat, no letting up.
Tracing route to secure.square-enix.com [61.195.53.13]
over a maximum of 30 hops:

1 5 ms 4 ms 4 ms 192.168.1.1
2 15 ms 14 ms 17 ms syn-107-013-016-001.res.spectrum.com [107.13.16.1]
3 636 ms 479 ms 504 ms lag-55.grnrnc0712h.netops.charter.com [174.111.103.22]
4 22 ms 23 ms 13 ms lag-24.apexncco01r.netops.charter.com [24.25.62.134]
5 27 ms 27 ms 20 ms lag-31.rcr01chrcnctr.netops.charter.com [24.93.64.186]
6 * * 30 ms lag-414-10.atlngamq46w-bcr00.netops.charter.com [66.109.7.196]
7 * * * Request timed out.
8 87 ms 75 ms 74 ms lag-412.dllstx976iw-bcr00.netops.charter.com [66.109.6.90]
9 * 83 ms * lag-401.tustca4200w-bcr00.netops.charter.com [66.109.5.228]
10 98 ms 85 ms 79 ms lag-1.pr2.lax10.netops.charter.com [66.109.5.241]
11 80 ms 74 ms 74 ms syn-066-109-007-090.inf.spectrum.com [66.109.7.90]
12 80 ms 76 ms 80 ms 203.181.106.173
13 185 ms 178 ms 186 ms 106.187.12.17
14 195 ms 187 ms 185 ms 27.85.227.105
15 187 ms 186 ms 182 ms 27.85.227.105
16 186 ms 191 ms 184 ms oteJIN301.int-gw.kddi.ne.jp [27.86.32.6]
17 187 ms 190 ms 182 ms 125.29.26.14
18 182 ms 186 ms 185 ms 133.208.191.149
19 175 ms 174 ms 171 ms 133.208.55.26
20 179 ms 173 ms 174 ms 219.117.144.122
21 183 ms 180 ms 187 ms 219.117.144.57
22 206 ms 207 ms 206 ms 219.117.146.133
23 209 ms 204 ms 178 ms 219.117.145.138
24 * * * Request timed out.
25 * * * Request timed out.
26 * * * Request timed out.
27 * * * Request timed out.
28 * * * Request timed out.
29 * * * Request timed out.
30 * * * Request timed out.

The workaround of deleting the boot file from documents > my games > final fantasy xiv a realm reborn works, but it has to be done each and every time in order to get the launcher to load properly.

Good morning! Thank you for posting in the Final Fantasy XIV Technical Support Forums.

We apologize for any inconvenience experienced when trying to play Final Fantasy XIV. Please try the following troubleshooting suggestions:

Open the control panel of the PC and go to ‘Network and Internet’. Once there select ‘Internet Options’
- Under the "General" tab, please delete ALL browser history.
- Under the "Security" tab, please move the slider to the lowest possible settings or no higher than "Medium"
- Under the "Privacy" tab, click “Advanced” and select ‘Accept’ under both First Party and Third Party Cookies.
- Under the "Advanced" tab, please make sure that "Allow software to run or install even if signature is invalid" is CHECKED.
- Make sure that all SSL and TLS (EXCEPT SSL 3.0) are CHECKED. [SSL 3.0 should be UNCHECKED]
- Hit "Apply" to save the settings, and then "OK, to close the Internet Options menu.
- Right-Click on the FFXIV launcher icon and select "Properties"
- Hit "Apply", then "OK" to save the changes.
- Please RESTART your PC now. Once your PC has been restarted, Right-Click the FFXIV launcher icon once more and select "Run as Administrator"
*Make sure your fire wall or antivirus program is not interfering with the game

Check to see if the following port ranges are opened on your router. You can contact your ISP and request they open them for you
▼TCP
54992 through 54994,
55006 through 55007,
55021 through 55040

- Try disabling background applications and do a clean boot by opening the task manager and selecting the “Start up” tab. Disable everything and then restart the PC.
- We suggest to power cycle the device and router by shutting down the Router and leaving the power supply unplugged for 30 mins. to an hour.
 
- Flush DNS: Within the "Command Prompt" of the device, please type the command "ipconfig /flushdns".
- Reset TCP/IP: Also within the Command Prompt, type the command "netsh int ip reset" and then restart the computer.
- Change local DNS: Please try changing the local DNS server to 8.8.8.8 and 8.8.4.4

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV.