I followed the usual procedure to upgrade my virtualenv to the latest version (0.101.2) from 0.95.x if I didn’t recall wrong.
But it upgraded to 0.96.5 only.
Is there a way to find out why it didn’t reach the latest one?
What version of Python do you have running.
Python version is 3.5.3
Sounds like that’s your problem. As far as I know that version is now deprecated. You’ll have to either update your Python version (a little bit involved) or backup your config and do a fresh install of HA.
For more details New version 0.94.0 - How update Python in a Pi3 from 3.5.3 to 3.7.3?
Thanks. I upgraded the whole Debian version.
Now I’m struggling while fixing all the changes they’ve made in configuration 
Unfortunately that’s the problem staying on a particular release for too long. All those breaking changes need to be identified between releases. Good luck identifying them.