External USB 3TB Drive Knocked Offline During Weekly AVG Scan

Update (week 2): My weekly system virus scan at 2:00am Saturday morning completed successfully again and my external WD USB 3TB drive (E:) drive was not knocked offline.  It seems the AVG repair you had me run resolved the previous issue of the weekly scan knocking my external USB E: drive offline.  At this point, I think we can consider this issue resolved.  Thanks very much for your help.  I'm glad the resolution was a relatively simple one.

Tried to reply to the email but thread on this but it bounced back to me.

Update: My weekly system virus scan ran as scheduled, at 2:00am.  It completed successfully and my external WD USB 3TB drive (E:) drive was not knocked offline like before.  It even found an infected downloaded program file (archives, on the E: drive) so I quarantined that too.  I will see what it does this next weekend, where presumably it doesn't find anything infected so scans and ends clean like it's done before.  If my external USB E: drive does not get knocked offline then, I will consider this issue resolved.  While preliminary, it seems running the AVG repair more than likely resolved this strange issue.

Hi Charles,

We'll certainly look into this & help you.
Initially, we request you to repair your AVG Antivirus Free as mentioned in this article & check if the issue persists.
If the issue persists after the repair, kindly reinstall your AVG Antivirus Free & check for the issue. Refer to this article to reinstall your AVG Antivirus Free after it's been uninstalled.
Please let us know if the issue still persists after repair & reinstall, we'll offer you further assistance to investigate this issue.
Thanks in advance. Keep us updated.

Just submitted this to Tech Support via email but maybe someone here has experienced the same thing and knows why this is happening, how to correct it.  Btw, I run a Dell T3400 PC, Quad core Intel CPU running Windows 10 Professional (64 bit) and using AVG Free.

Every Sunday at 2:00am my weekly scheduled AVG scan runs.  During this process, my external WD USB 3TB drive (E:) is knocked offline, requiring that I power-fail the drive to get it back so the PC sees it again. I have a second external USB drive, exactly the same except it's a WD 2TB drive (G:) that is never bothered, never knocked off line during this same weekly scan.  The 3 TB drive runs fine and shows no signs of any problems so I don't think it's the drive. 

From a STR perspective, the only constant is this only happens after this weekly AVG scan runs so is consistently reproduceable, happens every week.  Why is this happening and how can I fix this, other than get rid of AVG and find something else that doesn't do this?  Is there a log file that might show why this might be happening?  Perhaps AVG has a bug?

* Note: The only thing I haven't tried is disabling (shutting down) AVG before I go to bed Saturday evening so my weekly AVG scan does not run at 2:00am Sunday morning to see if my USB (E:) drive is online like it's supposed to be when I check Sunday afternoon.  This is becoming a big PIA dealing with this every week!

Many thanks for your response.  Just ran the repair for my AVG Antivirus Free as directed, which completed successfully.  The repair did not blow up my scheduled weekly scan settings so we will see what happens when that runs next Sunday morning (2:00am), as usual.  I will keep you posted.

Update (week 2): My weekly system virus scan at 2:00am Saturday morning completed successfully again and my external WD USB 3TB drive (E:) drive was not knocked offline.  It seems the AVG repair you had me run resolved the previous issue of the weekly scan knocking my external USB E: drive offline.  At this point, I think we can consider this issue resolved.  Thanks very much for your help.  I'm glad the resolution was a relatively simple one.

Hi Charles,

We'll certainly look into this & help you.
Initially, we request you to repair your AVG Antivirus Free as mentioned in this article & check if the issue persists.
If the issue persists after the repair, kindly reinstall your AVG Antivirus Free & check for the issue. Refer to this article to reinstall your AVG Antivirus Free after it's been uninstalled.
Please let us know if the issue still persists after repair & reinstall, we'll offer you further assistance to investigate this issue.
Thanks in advance. Keep us updated.

Tried to reply to the email but thread on this but it bounced back to me.

Update: My weekly system virus scan ran as scheduled, at 2:00am.  It completed successfully and my external WD USB 3TB drive (E:) drive was not knocked offline like before.  It even found an infected downloaded program file (archives, on the E: drive) so I quarantined that too.  I will see what it does this next weekend, where presumably it doesn't find anything infected so scans and ends clean like it's done before.  If my external USB E: drive does not get knocked offline then, I will consider this issue resolved.  While preliminary, it seems running the AVG repair more than likely resolved this strange issue.