Date & Time: 5/23/18 (~9:00 AM EST) to now
Frequency: Always
World name: Adamantoise
Character name: Lucina Liera
Class/Level: Summoner/30
Party or solo: Solo
In-game time: ????
Area and coordinates: Level 30 Summoner Quest Instance
Steps:
1. Tried to activate the solo instance for the class quest.
2. While in the instance I've got a disconnection error message.
3. Tried to log back in with the character, but will get immediately get rejected with the error code 90002.
4. Can log in to any other character. One on Moogle. And even a newly created character on Adamantoise. Only this character causes the issue.

Connection Specs
- Type of internet connection/provider: AT&T


■ PC Specs

To obtain the system information, open the FFXIV launcher and select Config → System Information → Display.

-=-=-=-=- System Information -=-=-=-=-

SYSTEM_OS Windows 8.1 64-bit (6.2, Build 9200) (9600.winblue_ltsb.170511-1554)
SYSTEM_CPU Intel(R) Core(TM) i3-4010U CPU @ 1.70GHz (4 CPUs), ~1.7GHz
SYSTEM_CORE_NUM SYSTEM_CORE_LOGIC 4 SYSTEM_CORE_PHYSICS 2
SYSTEM_BIOS A07
SYSTEM_LANGUAGE English (Regional Setting: English)
SYSTEM_MEMORY 3976.961MB
SYSTEM_VIRTUAL_MEMORY 134217727.875MB
SYSTEM_PAGE_FILE 7944.961MB
SYSTEM_STORAGE C:\ SYSTEM_HARDDISK_DRIVE SYSTEM_TOTALDISC_SPACE 456.800GB SYSTEM_FREEDISC_SPACE 256.702GB
SYSTEM_DIRECTX_VERSION DirectX 11
SYSTEM_GRAPHICS Intel(R) HD Graphics Family
SYSTEM_GRAPHICS_DEVICE \\.\DISPLAY1
SYSTEM_GRAPHICS_CHIP Intel(R) HD Graphics Family
SYSTEM_GRAPHICS_MAKER Intel Corporation
SYSTEM_GRAPHICS_VRAM 160.000 MB
SYSTEM_GRAPHICS_SHARED_VRAM 1760.000 MB
SYSTEM_GRAPHICS_DAC Internal
SYSTEM_GRAPHICS_DISPLAY_MODE 1366 x 768 (32 bit) (60Hz)
SYSTEM_GRAPHICS_DRIVER igdumdim64.dll,igd10iumd64.dll,igd10iumd64.dll,igdumdim32,igd10iumd32,igd10iumd32
SYSTEM_GRAPHICS_DRIVER_VERSION 10.18.0014.4414
SYSTEM_GRAPHICS_DRIVER_DATE 5/12/2016 10:06:22 PM
SYSTEM_GRAPHICS_DRIVER_LANGUAGE English
3.0
SYSTEM_GRAPHICS_PIXEL_SHADER 3.0
SYSTEM_GRAPHICS_VERTEX_TEXTURE SYSTEM_SUPPORT
SYSTEM_SOUND Speakers (Realtek High Definition Audio)
SYSTEM_SOUND_DEVICE_ID {9BBB1A69-E183-40A0-B81D-ED8CF66B43C5}
SYSTEM_SOUND_DEVICE_NAME RTKVHD64.sys
SYSTEM_SOUND_DRIVER_VERSION 6.00.0001.7023
SYSTEM_SOUND_DRIVER_LANGUAGE English
SYSTEM_SOUND_DRIVER_DATE 8/21/2013 4:50:02 PM
SYSTEM_INPUT {6F1D2B60-D5A0-11CF-BFC7444553540000}
SYSTEM_INPUT_NAME Mouse
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 3 SYSTEM_GAMEPAD_BUTTON 5 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {6F1D2B61-D5A0-11CF-BFC7444553540000}
SYSTEM_INPUT_NAME Keyboard
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 128 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {B27F9280-62C2-11E4-8007444553540000}
SYSTEM_INPUT_NAME HID-compliant consumer control device
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 10 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {B1FFDB30-62C2-11E4-8001444553540000}
SYSTEM_INPUT_NAME Touchscreen
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {B2504520-62C2-11E4-8002444553540000}
SYSTEM_INPUT_NAME Touchscreen
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {B250BA50-62C2-11E4-8003444553540000}
SYSTEM_INPUT_NAME Touchscreen
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 0 SYSTEM_GAMEPAD_FOV 0
SYSTEM_INPUT {B25DB2A0-62C2-11E4-8005444553540000}
SYSTEM_INPUT_NAME Airplane Mode Switch
SYSTEM_INPUT_REMARKS SYSTEM_GAMEPAD_AXIS 0 SYSTEM_GAMEPAD_BUTTON 1 SYSTEM_GAMEPAD_FOV 0

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Relevant info regarding this issue in a forum post:
Quote Originally Posted by Leahra View Post
I received this email from submitting a ticket will the support center...

Thank you for contacting the North American SQUARE ENIX Support Center. We appreciate you taking the time to contact us for assistance.

We apologize for any inconvenience you may be experiencing while attempting to log in. This specific error is an error regarding character data. The error is most commonly caused by an improper disconnection from the servers during gameplay. As the game servers still recognize the character as being logged in due to the improper disconnection, the character cannot be logged into again. Unfortunately, there is no manual way to communicate to the servers that the character is no longer logged in, nor is there a way to manually log the character out. The character will eventually be recognized as logged out, though this time can vary depending on multiple factors, such as the area the character was in when the disconnection happened. We recommend trying to log into that character at a later time, but if the problem persists, please submit a bug report within the official FINAL FANTASY XIV forums at: http://forum.square-enix.com/ffxiv/forum.php