We had a Qlik sense server 3.2 SR2 instance which we required to upgrade to the June 2017 version. I tried several times without success. I reviewed a lot of posts here but none of them described my situation therefore I tried almost most of the solutions related to upgarde problemas even if they were not describing my problem. This strategy helped me to learn a lot of tips, but it didn't solved my problem and then I decided to raise my problem to support.
For all these people that had a problem like mine I want to share my experience hoping that it might help somebody in the future.
My logs showed a failed postgress installation, sometimes this logs are difficult to read. I noticed the error is described in the same link that comes above
I noticed that it was running it on a windows server 2008. I discovered that I should upgrade to 2012 and install all the patches Installing Qlik Sense June 2017 on windows 2008 server R2. Patches solved a problem with a stalled hub, in other words , upgrading to 2012 was not enough for my Qlik 3.2 SR2 instance to run. This was not the solution to my problem but this was a really helpful (and a must) post
Some posts talked about a C:\Programdata directory. I had a hard time finding it. I discovered that this is a hidden directory in windows 2012. It turned out that is very helpful to have access to this directory. Many posts in this forums now make sense
I removed the Qlik sense service account from the Performance Monitor Users group as mentioned in the link above, restarted the server and tried the upgrade again and it worked. Now I have a fully working instance of Qlik sense June 2017