Comment 56 for bug 1853369

I am having the similar issue on my Dell XPS 8930 Desktop when tried upgrading from 18.04 LTS to 20.04 LTS. Mine is dual boot linux with Windows 10.
I had successfully running Windows 10 and Ubuntu Linux 18.04 LTS system for almost 2.5 years. Then heard about 20.04 LTS - seems to be smooth installed-i wanted to try it. I followed this link Did everything from command line. Everything went fine. I have Linux installed on PCI NVME SSD and Windows 10 on normal SSD. I used Windows boot loader as the default entry and Ubuntu Linux to be selected if i want to go to Linux. As per that link, i installed not using kernels to clean up some space. I was getting purple grub screen.

But after this upgrade - i get this black grub screen.
on which Linuxes - there are two entries - i don't know which one is default. But if i try to select either of the linux - it doesn't boot Linux and it's all dark screen.

Though on Grub - i can select the entry for Windows and it boots it without any issues.

What went wrong? How to come back to normal life with this upgraded ubuntu Linux 20.04 LTS? I can select the advanced option and then tried booting 5.4.0-31-generic(kernel which comes with Ubuntu Linux 20.04 LTS) After that it displays: Loading Linux 5.4.0-31-generic ... Loading initial ramdisk
and then it freezes
What could be the issue? But after selecting Advanced options for Ubuntu when i select Ubuntu with Linux 4.15.0-101-generic it shows me same messages Loading Linux 4.15.0-101-generic… Loading initial ramdisk… but not getting stuck or freeze and finally loads new Ubuntu Linux 20.04 LTS

What's going on here? I checked that 20.04 LTS is installed and working with this choice root@ashu-XPS-8930:/home/ashu# cat /etc/lsb-release

I was upgrading using this command on the command line:
sudo do-release-upgrade -d