I have been using avast for quite a while already - no problem. However, today for the very first time I encountered a problem with avast and it was this error message (indicated subject title) when I clickec on update virus definitions.
I use avast Free Antivirus on Win 10 Pro, which just had an update yesterday with “Cumulative Update for Windows 10 Version 1607 for x64-based Systems (KB3200970)”.
I just did a repair of the program with the uninstaller but the error still show up.
I checked my system, RAM only about 40% in use and I still have 700 GB of free space on hard drive.
700 Gig isn’t a lot of room. The operating system itself needs and uses quite a bit.
I suggest you free up some room on your HD. Maybe even invest in a larger HD.
Eddy, I have reinstalled avast and it is now working properly.
Nevertheless, I just like to share that prior to the reinstallation, when I first powered up my PC yesterday I could update virus definitions but could not run Quick and Full scans. I was able to run Boot-time scan, though. Also, the real time shields got disabled by itself.
Coincidentally, my PC was also acting very sluggish - very slow bootup and shut downs. Thus far, this seemed to be resolved after the reinstallation of avast.