Hi,
With Suricata 6.0.x, there should be exactly one error message if the output file was successfully opened but couldn’t be written to.
Could you check suricata.log for a message containing "error while writing to"?
Additionally, when Suricata terminates gracefully, the following message should be logged if there were errors interacting with the file (eve.json) – look for "There were NNN output errors to eve.json"
All Suricata issues are tracked at Redmine: https://redmine.openinfosecfoundation.org/projects/suricata
When opening a ticket, please include as much contextual information as you can (error logs, etc) and be sure to redact/omit anything you can’t share with the community.