This can sometimes happen if you have malwarebytes realtiime protection turned on. Try disabling realtime protection and also temporarily disable avast as before.

Disable MBAM Real-Time protection
  • Right-click on the MBAM icon in the System Tray and uncheck Enable Protection.
  • When asked, "Are you sure you want to disable the MBAM Protection Module?", click Yes.
  • Right-click on the MBAM icon again and then uncheck Start with Windows.
  • Restart your computer for the changes to take effect.