The only thing you can do at this point is revert to an earlier version of avast. Here’s a tutorial to do so by Matthew81 https://forum.avast.com/index.php?topic=189195.msg1328202#msg1328202
And for avast free?
Beacose if i try to install offline 2272 by filehippo i install again the version 2276
The offline installer for avast free is here http://filehippo.com/download_avast_antivirus/68667/
Do steps 3, 4, and 5 in matt’s tutorial and you should be good to go 
Make sure that after you downloaded the 2272 installer and uninstall utility, you disconnect your internet, and don’t turn it back on until avast is installed and configured to only manually update. Because it’s the free version you don’t need to activate or anything.
Problem already fixed - https://forum.avast.com/index.php?topic=189131.msg1328660#msg1328660
The problem has been corrected click this link!!! Default Fix: Avast Background service is not running
Users of Avast Antivirus who upgraded to the latest version 12.2.2276 are finding that their Avast Background service is not running as a result of which the antivirus does not work properly.
To fix this issue, you may run C:\Program Files\AVAST Software\Avast\AvastEmUpdate.exe and then reboot your computer.
If this does not work for you, download the latest installer from the Avast site - as they have now fixed the issue - and install it on your Windows PC.
Thanks for a nice summary.
Just one comment on this: the problem was with the UI incorrectly reporting the state of the service, not that the service itself wouldn’t be running, and also the anti-virus protection was uninterrupted.
You can check for avast service running inside task manager, or services control panel.
Thanks. Lukas
Only enable extensions avast browser , is now running and logged.
os: w7 64
browser: chrome