I was unable to login to the Gnome desktop environment immediately after I upgraded to Kali 2019.4.

I used CTRL/ALT/F2 to get to a Console that would allow login.

I then solved my issue by using my Console login to install and configure the Kali XFCE desktop environment as described under SWITCH DESKTOP ENVIRONMENTS here:

https://www.kali.org/docs/general-use/xfce-faq/

I rebooted and was immediately able to login to and switch between desktop environments.


My post-install working state:

root@kali:~# cat /etc/os-release
PRETTY_NAME="Kali GNU/Linux Rolling"
NAME="Kali GNU/Linux"
ID=kali
VERSION="2019.4"
VERSION_ID="2019.4"
VERSION_CODENAME="kali-rolling"
ID_LIKE=debian
...

root@kali:~# lspci
00:00.0 Host bridge: Intel Corporation 8th Gen Core 4-core Processor Host Bridge/DRAM Registers [Coffee Lake H] (rev 07)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16) (rev 07)
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 630 (Mobile)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:12.0 Signal processing controller: Intel Corporation Cannon Lake PCH Thermal Controller (rev 10)
00:14.0 USB controller: Intel Corporation Cannon Lake PCH USB 3.1 xHCI Host Controller (rev 10)
00:14.2 RAM memory: Intel Corporation Cannon Lake PCH Shared SRAM (rev 10)
00:14.3 Network controller: Intel Corporation Wireless-AC 9560 [Jefferson Peak] (rev 10)
00:15.0 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH Serial IO I2C Controller #0 (rev 10)
00:15.1 Serial bus controller [0c80]: Intel Corporation Cannon Lake PCH Serial IO I2C Controller #1 (rev 10)
00:16.0 Communication controller: Intel Corporation Cannon Lake PCH HECI Controller (rev 10)
00:17.0 SATA controller: Intel Corporation Cannon Lake Mobile PCH SATA AHCI Controller (rev 10)
00:1d.0 PCI bridge: Intel Corporation Cannon Lake PCH PCI Express Root Port #9 (rev f0)

Hope this helps!