I am a different user with the same problem ("transcoding error").
I use PE14.
I do not get the error when I burn a disk as AVCHD. The videos (I have encountered the problem on more than one video) are about an hour long, but AVCHD should be more resource-hungry than DVDs and yet I have no problems burning AVCHD disks.
But I always get the error when I attempt to burn the videos as a DVD. I also encountered the error when simply requesting the creation of a DVD ISO image.
I have menu markers, but I do not have one at the end of the video.
The error appears during the "burning to the disk" phase of the process at different percentages of the whole process. The error does not appear during the "encoding media" phase.
I am producing the videos of a recent tour of the USA we took with my brother in law and his wife. For us I have burned the disks as AVCHD. But the wife of my brother in law would like a DVD version to show her mother who has an old video player. Our videos (five of them) have been burned without any difficulty and work fine, but I cannot produce the DVD version.