When using the NVENC H.264 encoder on Nvidia graphics card, artifacts can appear in the session window. This issue seems to be a matter of two different things: a recent update of the Nvidia graphics card drivers that is triggering the problem and also a small bug in one of the FFMPEG libraries that we use for decoding. We are updating such libraries to definitely resolve the issue.

As a workaround, it is possible to disable use of hardware encoding and use software H.264 encoding instead. To enable software encoding, uncomment and change the 'EnableHardwareEncoding' key in the 'node.cfg' configuration file as follows:

EnableHardwareEncoding 0

Summary: Resolved in version 6.10.12 released on 2020-05-12.