I have a new Lenovo ideapad 5 14AR05. I successfully installed Ubuntu 20.04 LTS with an encrypted harddisk. I then upgraded the kernel to 5.8.13, because I could not use an external monitor with the default kernel. It worked and I'm pretty sure I successfully restarted a couple of times trying to get my trackpad to work. Then I installed unity, and I couldn't boot up in the new kernel anymore, it's stuck on the cryptsetup (before typing password) and gives the following error:
volume group vgubuntu not found
Earlier in the boot up I also get:
initramfs unpacking failed: Decoding failed
But I'm not sure if that's related. I can boot up in the default kernel, and because adding unity was the last thing I did, I removed it again, but that probably had nothing to do with it, and it still won't boot up.
I did look at several other questions mentioning this, but I couldn't figure out exactly what applied in my situation.
eta: I confirmed that the uuid in /etc/crypttab is the same as the one in /dev/disk/by-uuid/ and is the one that the cryptsetup is trying to load.