Thanks for the input and suggestions. I tried the delay option, but it didn’t work so I undid the change. On a hunch, I uninstalled VirtualBox in case the ‘network’ it creates was causing avast to hiccup. It either didn’t work or I didn’t wait long enough, but after reinstalling VirtualBox and rebooting yet again, avast seems to be back to normal. Whether it was indeed something with VirtualBox or something else or simply voodoo, I have no idea but for the past three reboots avast has loaded fine. Hopefully it stays this way.

Thanks again.