sudo apt-get update error E: part of the index file download failed. If you ignore them, they will revert to the old index file.

Solution 1:

The corresponding PPA can be removed

cd /etc/apt/suorces.list.d

etc. **. ** list. list.bak

 

Solution 2:

Change source

cp /etc/apt/source_list /etc/apt/source_list.bak

sudo gedit /etc/apt/source_list

Add the missing list