I'm trying to upgrade Ubuntu 18.04 to 20.04. Upgrading stops at:

Preparing to configure libgraphene-1.0-0 (amd64)

while the terminal says:

HTTP request sent, awaiting response... Read error (Connection timeout) in headers

It happened for the second time today. When I upgraded a week ago everything was fine.

While I was writing this, upgrading continued after half an hour of waiting, so anyway I'm wondering what was happening.

  • 5
    As that link says, Adobe Flash reached end of life on December 31, 2020. I guess that's why you're getting that message now and not a week ago. – Ray Jan 4 at 10:07
  • A. Eaxon: I see that you accepted my answer. While I'm glad it was helpful, it would be valuable if you could tell us more exactly what the problem was in your case. Did you encounter the issue due to some Adobe repo in the apt sources, or was it simply due to some of the packages I mentioned in the answer? – Gunnar Hjalmarsson Jan 5 at 8:22
  • The upgrader sent requests three times waiting for responses from 8 to 20 minutes. After the third try failed, "Giving up" message appeared and the upgrading continued and finished successfully. Not sure, but I believe that removing Flash packages should work for others who encounter the same problem. – A. Eaxon Jan 5 at 12:37
  • Is there a way to force skip the adobe url lookup if the upgrade process hangs? – membersound Jan 6 at 14:47

As Ray pointed out in a comment, Flash became end of life at the year end. It looks like you should uninstall all the Flash related stuff before upgrading. I'm thinking of these packages in the Ubuntu archive:


If you have some repository provided by Adobe enabled, you should disable that from your apt sources.

If you installed Flash some other way but through .deb package(s), e.g. directly from the Adobe site, you should know best yourself which files to remove.

  • 1
    for others if you get the same error, be patient. ubunutu gives up on 3rd try and then continues installation. So you might be wondering waiting for it to succeed and watching the screen for 20-25 min, hang on, it will succeed. I was in this problem at the time of writing and had the same result. – 89n3ur0n Jan 20 at 12:24

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