Unusual message sent back to sftp

The log for one sftp job this morning included this line:

Couldn't get handle: Failure

This immediately followed a message stating that a file was Uploading.

Based on the exit status, the program logic did not treat this as an
error. But, I checked with the remote site, and none of the three
files had been received.

What is this message stating?
Why wasn't the return code for the sftp session set to non-zero? The
PTF that enables this has been applied and it has worked in the past.

Thanks,

John McKee