Description of problem: Please update gnutls to upstream version 3.6.5 (or newer) to handle the record_size_limit extension. https://gitlab.com/gnutls/gnutls/commit/ba4c0ced0159c1fc871c5c61a24b7e6927bbe9b1
gnutls-3.6.5-1.fc29 has been submitted as an update to Fedora 29. https://bodhi.fedoraproject.org/updates/FEDORA-2018-79f7540a1e
This update fixes my VNC problems, thanks! Bodhi karma updated.
gnutls-3.6.5-1.fc29 has been pushed to the Fedora 29 stable repository. If problems still persist, please make note of it in this bug report.