Stuck trying to upgrade from Ubuntu 18.04 to 20.04 'multiverse' (component misspelt in sources.list?)

When I tried to upgrade from Ubuntu 18.04 to Ubuntu 20.04 I I got stuck. While upgrading, it shows: 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

W: Skipping acquire of configured file 'multiverse/binary-amd64/Packages' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/i18n/Translation-en_IN' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/i18n/Translation-en_GB' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/i18n/Translation-en' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/Components-amd64.yml' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/icons-48x48.tar' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/dep11/icons-64x64.tar' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)
W: Skipping acquire of configured file 'multiverse/cnf/Commands-amd64' as repository 'http://archive.canonical.com/ubuntu  bionic InRelease' doesn't have the component 'multiverse' (component misspelt in sources.list?)

I tried sudo nano /etc/apt/sources.list, and it says the same line already exists in sources.list.

deb http://archive.canonical.com/ubuntu  bionic partner

I found a solution on the internet. Replace this line: deb http://archive.canonical.com/ubuntu bionic multiverse partner with this line: deb http://archive.canonical.com/ubuntu bionic partner. But the same line was already present in my sources.list. Now I'm unable to upgrade from Ubuntu 18.04 to Ubuntu 20.04.