Sorry to re-open the thread but after carefully looking at the remedies proposed, I’m still unable to launch Avast (getting the message invalid argument - I downloaded Avast today). I changed in the terminal the default value for shmmax to 128000000 (and even later to a higher one) as suggested in this thread but nothing changes.

I don’t know if there is something new about.

I’m under Ubuntu 14.04 LTS.

Thanks

PS: to be more precise, I can launch Avast if I delete the file 400.vps in the terminal. Then I launch the definition update and it ends up in “reinitialization of avast engine failed after the database update - the application will terminate” plus “An error occurred in avast ! Argument invalid”; checking in the terminal the file 400.vps is back.