Let's cut the fluff from the avast team and nonsense guesses about rights.
I have my user's error log for this problem and the error message is identical to that which started this thread. It says over and over "cannot find the file specified" once for ever avast server in the servers.def file and then one more on top of that for the servers.def file.
There was and continued to be absolutely no problem with the user's servers.def file, no need to repair avast and no need to re-download the servers.def file.
I am sorry to be critical but the error log is just as useless to the average user, and the comments here from kubecj leave me feeling that, on this issue, the avast team is "asleep at the wheel".
What this error message meant - plain and simple - was that avast could not connect to any avast server.Why cannot it just say that to the user instead of that garbage message?
It's not a common error at all
If it is not a common error then why are there so many complaints about the VPS update process in this forum?
What may be the source of errors I don't know
Isn't it the job of the avast team to try to overcome not knowing the problems users are having?
I rather suspect that you are not seeing too many complaints about this from the nice clean controlled environment of your business users. However, many of your users are running the rather cluttered, uncontrolled environment of home systems where many of them hardly ever see a program they don't want to download.
Nowadays everyone and his dog wants to have a process run at startup to determine if there are any updates to run or new advertisements for their software to show or simply to get them connected to their DVR and to their favorite IM/VoIP/game. That's all on top of the ever present Windows update process.
The avast VPS update is competing with all this. I do not know the design structure of the startup processes but have to wonder if one of them running at "below normal" priority is contributing to this problem at a time of system and network stress.
It is worth noting that Tech's recommendation to increase the startup delay does seem to be effective in helping a number of users overcome this problem, unfortunately the delay option is not available via the gui and requires users to manually edit the avast4.ini - which should not be the way average users have to manage avast.