Cache Refresh Stuck At 100%

I've been trying to update my software to the latest version, but after I opened Software Updater, it shows Failed to download repository information. After that, I headed to Software & Updates. After making some changes, it showed that my software cache is out dated and needs to be refreshed. After I pressed yes, it opened the Cache Refresh window. After it ran to 100% (I think) an Ubuntu error report window pops up. After that, it stuck. Is it a bug? Or is it just my computer?

Solution 1:

Here's the standard /etc/apt/sources.list file :

deb http://archive.ubuntu.com/ubuntu/ focal main restricted
deb http://security.ubuntu.com/ubuntu/ focal-security main restricted
deb http://archive.ubuntu.com/ubuntu/ focal-updates main restricted

Copy-paste it after making a backup of your current source.list file then run sudo apt update.And also when you want to add a PPA note that the codename of the ubuntu 20.04 is FOCAL not eoan which is 19.10.