Problem: Linux mint update manager could not refresh the list of packages.
Easy & Quick Fix: Run Below commands in terminal and then try refreshing the list of updates.
- 1) sudo rm /var/lib/apt/lists/* -vf
- 2) sudo apt-get update
This problem was easy to fix but hard to find solution. The solution is provide by the coutsey of Linux mint Forum user dawgdoc
Hope it Helps!