UPDATE/ unknown error

I am getting a popup that says I need to update my Avast pro.
when I click up on the Update button it goes to Downloading file servers.def.vpx
but there is no progress. after a short while I get the message unknown error
This sequence repeats itself until I close the window.
It has done this for the past three days.

can any one tell me what is going on and a solution.

Please try the following: Repair Avast:
Control Panel> Program and Features (Add/remove program)>Select Avast> Select Repair. Reboot when completed
https://www.avast.com/faq.php?article=AVKB204

If Repair doesn’t fix the problem, try the following:
Clean Install of Avast:
https://goo.gl/4Ptzkf
If you need additional help with the Clean Install, watch this:
https://youtu.be/p-h3myRD51A

This is still a persistent issue, and I hate having to reinstall and lose all my settings. Is this being fixed?

Under settings, Save your settings:

https://screencast-o-matic.com/screenshots/u/Lh/1522870755004-92707.png

Now follow the instructions I’ve already provided. After the new install,
go back to settings and Restore the saved settings.