[Potentially unnecessary details will be in small font to save your time. I include these to be thorough but don't want people to have to bother reading through everything. Feel free to skip these entirely - They only provide background detail on what I was thinking while making this mistake.]
So I'm having a problem with my relatively fresh install after changing a single line in a config file. I'd like to understand why this happened and hopefully fix it.

I really dislike the Gnome 3 "Hot Corner" feature since I keep activating it accidentally and I feel no system should have any features where simply hovering the pointer over a portion of the screen without clicking activates something, so I decided to look for a way to turn the thing off. The regular settings available from the various GUI menus had no way to turn this off (damn shame), so I did some Googling, and found that it can supposedly be turned off by changing a line in /usr/lib/gnome-shell/libgnome-shell.so

In case anyone wants to see, here are some of the links that got me feeling brave about messing with my configs:https://www.linuxquestions.org/quest...eature-880221/(This link actually points to another file but after not being able to find it, another Google search told me this file got switched to /usr/lib/libgnomeshell.so in future Gnome versions since that forum post)

The change suggested involved modifying two variables in the file:
Code:
this.actor = new Clutter.Actor({ name: 'hot-corner-environs',
x: this._x, y: this._y,
width: 3,
height: 3,
reactive: false });

this._corner = new Clutter.Rectangle({ name: 'hot-corner',
width: 1,
height: 1,
opacity: 0,
reactive: false });
So I used nano to edit the line as suggested... Changed them both from TRUE to FALSE and as soon as I saved and exited the file - BOOM, GUI crashed. I didn't even have to ALT-F2 and R to reboot the GUI - it happened as soon as I saved and quit the file. I just couldn't see anything but black until I switched over to TTY2.

Trying to launch X from TTY2 failed, saying it cannot establish any listening sockets as an X server is already running.
I tried manually editing the file back to its original state but that didn't work.
My second thought was maybe I accidentally changed another character too by hitting a key when I thought I didn't, so I booted up a clean install of Kali on a different laptop and copied the file on that instance to my broken install, replaced the file and rebooted - still no change.

Since I pretty much reversed the only change I'm aware of having made and still haven't been able to solve my problem, I decided to ask you guys. What do you think could be the problem here?

-TECHNICAL INFO-
My Kali is installed on a Dell Inspiron 15. Below you can find system information and certain logs:

Code:
root@kali:~# uname -a
Linux kali 4.9.0-kali3-amd64 #1 SMP Debian 4.9.18-1kali1 *2017-04-04) x86_64 GNU/Linux
Code:
root@kali:~# lspci
[13917.833913] nouveau 0000:08:00.0: bus: MMOP write of 0000001f FAULT at 6013d4 [ IBUS ]
[13917.835101] nouveau 0000:08:00.0: bus: MMOP write of 0000001f FAULT at 6013d4 [ IBUS ]
00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 0b)
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b)
00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev 0b)
00:16.0 Communication controller: Intel Corporation 8 Series HECI #0 (rev 04)
00:1b.0 Audio device: Intel Corporation 8 Series HD Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 1 (rev e4)
00:1c.2 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 3 (rev e4)
00:1c.3 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 4 (rev e4)
00:1c.4 PCI bridge: Intel Corporation 8 Series PCI Express Root Port 5 (rev e4)
00:1d.0 USB controller: Intel Corporation 8 Series USB EHCI #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation 8 Series LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 8 Series SATA Controller 1 [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation 8 Series SMBus Controller (rev 04)
06:00.0 Network controller: Broadcom Limited BCM43142 802.11b/g/n (rev 01)
07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller (rev 07)
08:00.0 3D controller: NVIDIA Corporation GF117M [GeForce 610M/710M/810M/820M / GT 620M/625M/630M/720M] (rev a1)
Code:
root@kali:~# X
_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
_XSERVTransMakeAllCOTSServerListeners: server already running
(EE) 
Fatal server error:
(EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE) 
(EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
(EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
(EE) 
(EE) Server terminated with error (1). Closing log file.
Code:
root@kali:~# gdm3
This command just hangs and does nothing until I CTRL+C.

Code:
root@kali: cat /var/log/Xorg.0.log
[  4127.121] _XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
[  4127.122] _XSERVTransMakeAllCOTSServerListeners: server already running
[  4127.123] (EE) 
Fatal server error:
[  4127.125] (EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE) 
[  4127.126] (EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
[  4127.130] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[  4127.131] (EE) 
[  4127.132] (EE) Server terminated with error (1). Closing log file.
Also, I couldn't upload my DMESG output either in this post or in the attachments - I'm guessing it'll be necessary. I suppose I can try adding it to a reply to this post. Hopefully that'll work.

Thanks in advance to anyone willing to help out!