This bug has been added to the tracker:
https://winscp.net/tracker/975

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

With further investigation, I found the background refresh of remote panel to be the cause. Perhaps it is also tied to the specific server I'm dealing with, but if the Preference "Refresh remote directory panel" is unchecked, the app downloads to completion. By extending the interval only proved this was the issue in my case.

-Chris

When using WinSCP previously, could download entire site, sometimes many, many hours long with no problem. Now when I attempt download WinSCP errors and closes after ~3 minutes.

Log:
Problem Event Name: APPCRASH
Application Name: WinSCP.exe
Application Version: 5.1.3.2881
Application Timestamp: 00000000
Fault Module Name: WinSCP.exe
Fault Module Version: 5.1.3.2881
Fault Module Timestamp: 00000000
Exception Code: c0000005
Exception Offset: 0028d6b3
OS Version: 6.1.7601.2.1.0.256.1
Locale ID: 1033
Additional Information 1: 0610
Additional Information 2: 06107b45b2c44bc159ef4f2e3648f506
Additional Information 3: d427
Additional Information 4: d427c4ede0d5c8e32bae5a35b868525d

(if that helps)

Using Win 7 (x64), AVG firewall, WinSCP 5.12 began to error yesterday, upgraded to 5.13, same issue - uninstalled then reinstalled fresh 5.13 - same issue.

Added HP printer driver yesterday is only change to OS. Need to investigate if problem with WinSCP or with AVG and WinSCP together is happening to others -

Thanks in advance for any help with this issue.

-Chris