Hang when copying a file to remote S/FTP site

We have sucessfully using WinSCP for a couple of years now. Two weeks ago we started having a problem where the first 32K of a 100K file will be transferred to the remote site but then the copy terminates. This happens when I manually copy the file also. Attaching log file. from a manual copy.

Can you upload the file using any other SFTP client? If you can, please post its verbose log file.

Turned out to be Microsoft Security Patch KB5003197 causing the problem.

Thanks for your feedback.