qBittorrent - CRC Errors

[exie 1]

Been very happy with AirVPN (2.18.9 with wintun) and qBittorrent (v 4.2.5) up until a few days ago, when multiple downloads slowed to a crawl and then stopped with the message ERRORED: Cyclic Redundancy Check.
Swapped AirVPN servers which gave temporary improvement until same thing happened. Deleted torrents and tried others - all start fast, then die with the above error. Hard drive been checked, OK. Checked for nasties with Malwarebytes, none reported.
Looked on qBittorrent website but didn't find anything. Anyone any ideas?
Exie

[OpenSourcerer 1435]

14 hours ago, exie said:

Hard drive been checked, OK.

What exactly did you check and how?
RAM is another point of failure, since all BitTorrent clients use some form or read and write cache by default. You can check memory offline with memtest86+. There's an auto-flashing executable for Windows 7+. Flash the tool onto a USB drive and boot from it. Depending on your RAM size and clock speed this can take 30 minutes (8 GiB DDR4-3200) or several hours (32 GiB DDR4-2133). But any errors will pop out red in the lower half of the screen. If that is the case, you should test every bank separately to determine the faulty one.

It seems the error is on qBittorrent's side. There are reports that qBittorrent v4.2.5 is faulty. If you can, downgrade one or two minor bigfix versions back and check again. Edited ... by giganerd
New info

[exie 1]

14 hours ago, giganerd said:

What exactly did you check and how?
RAM is another point of failure, since all BitTorrent clients use some form or read and write cache by default. You can check memory offline with memtest86+. There's an auto-flashing executable for Windows 7+. Flash the tool onto a USB drive and boot from it. Depending on your RAM size and clock speed this can take 30 minutes (8 GiB DDR4-3200) or several hours (32 GiB DDR4-2133). But any errors will pop out red in the lower half of the screen. If that is the case, you should test every bank separately to determine the faulty one.

It seems the error is on qBittorrent's side. There are reports that qBittorrent v4.2.5 is faulty. If you can, downgrade one or two minor bigfix versions back and check again.

[exie 1]

Thanks for replying Giganerd.
To respond to your first post, I first checked my event log and found many Event 7, Event 51, Event 153, messages. I have a multi-disc setup (excluding my CDROM) of 7 physical drives (some partitioned) with several external/USB3 drives. As you probably know, identifying what drive actually is " \Device\Harddisk4\DR4" and " Disk 4 (PDO name: \Device\0000003e)" requires tedious research. (Another Microsoft triumph.) So I invoked an elevated command line prompt and ran chkdsk on what Disk Management reported as Disk 4 - it came out clean. However, you were right - the guilty drive failed totally overnight and it wasn't the drive to which I thought the Event Log errors referred. It was one of a mirrored pair so fortunately I lost minimum data, and that which for some reason was lost I could restore through a backup. To Do List: Learn how to determine actual drives when reported in Event Log; Don't trust Win GUI when checking discs!
Cheers, Exie

[OpenSourcerer 1435]

Or, you know, don't trust Windows in doing anything right. But that could be the Linux user in me speaking