When I was updating suddenly the process aborted with the message:

Could not calculate the upgrade 

An unresolvable problem occurred while calculating the upgrade. 

This was likely caused by: 
* Unofficial software packages not provided by Ubuntu 
Please use the tool 'ppa-purge' from the ppa-purge 
package to remove software from a Launchpad PPA and 
try the upgrade again. 

If none of this applies, then please report this bug using the 
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. If 
you want to investigate this yourself the log files in 
'/var/log/dist-upgrade' will contain details about the upgrade. 
Specifically, look at 'main.log' and 'apt.log'. 

Restoring original system state

Reading package lists... Done    
Building dependency tree          
Reading state information... Done

Please help me with update to Ubuntu 20.04 from 18.04.

  • 1
    The easiest way to guarantee an update is to remove all 3rd party software (ie. return to only using Ubuntu repository software), perform the upgrade, reboot then add back any 3rd party software required. If you filed the bug it mentioned, you can look there for packages creating the issue(s) then remove, or the logs as mentioned in your paste. A re-install (without format) is actually fastest in my experience. – guiverc May 12 at 11:46
  • 1
    Did you "If you want to investigate this yourself the log files in '/var/log/dist-upgrade' will contain details about the upgrade. Specifically, look at 'main.log' and 'apt.log'." ? – heynnema May 12 at 14:09


  • Go to Software & Updates
  • Go to Ubuntu software
  • In the Download from menu select main server

Then try to update Ubuntu. It worked very well for me.

| improve this answer | |

You have to remove third party repository. You can do it using one of two method:

Using the GUI (Software & Updates):

  1. Open Software & Updates app.
  2. Switch to Other Software tab.
  3. Uncheck all checkboxes (it will prompt for password first time).
  4. Retry upgrade to 20.04.

Using terminal:

  1. Issue this command on terminal:

    cd /etc/apt/sources.list.d
  2. Using an editor like nano or vi comment all uncommented line (put a # character at the beginning of line) in all files. (You need to use sudo) (You have to open all files one by one) (Uncommented line indicates those lines which don't start with a # character.)

  3. Retry upgrade to 20.04.
| improve this answer | |
  • i tried "Using gui method" it didn't work – Greek Sachdeva May 12 at 17:26
  • Please elaborate "Using terminal method" – Greek Sachdeva May 12 at 17:26
  • @GreekSachdeva Do you know how to use terminal and text editors like nano? If yes, then add a # character at the first of every line of every files at /etc/apt/sources.list.d . – Akib Azmain May 12 at 17:39
  • Nope i dont know – Greek Sachdeva May 12 at 17:53
  • how can i update to 20.04 wihout losing data – Greek Sachdeva May 12 at 17:54

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