Export failing

I am unable to export any video to any destination. I am using color finale to grade my videos. Sometimes I am able to export to specific locations but its pretty random when it wants to work. When the export fails I am given NO message or error. It just stops loading and goes back to normal before export. Any help? Thanks

When I encounter these oddities I'll test export the first 5 minutes to see how things go. At times I'll get the vague 'don't have permission to write to the selected location' error but other times I'll learn via incremental exports (0-5 min, 5-20 min, 20-40 min) I'll discover just where the export is failing.

(I recall coming across an odd single black frame in the original video that was kicking things out of whack. Deleted frame & things were good again.)