Adobe Media Encoder encoding single "Media Offline" frames

Hello there,

I am using Adobe CC 2017 Software on a Workstation running on Windows 10 and hoping to find help regarding one particularly strange AME CC 2017 issue I am struggling with:

I exported my sequence to AME from AE. I imported the Sequence to After Effects from a PP Project (Import -> Premiere Pro Project -> sequence name) which I used to cut the Material and to do Sound Editing & Mastering in Audition and a little in Wavelab. After Effects was used to do Color Correction (SA CF 3) as well as to add a Start- & End-Sequence and Logo embeds.

The length of the final film - a recording of a panel discussion - is a little over 1h 54m. The source material is stored on a NAS and accessed via local Network (.mov files recorded on an AJA KiPro).

My issue is this:

I export H.264 1920x1080 25p, the encoding takes about 15 hours 'til it's done, and while I am watching the final result, with which I am initially rather happy with, I stumble upon a single one of these wonderfully classical  "Media Offline" Frames at about 11m 18s. I am importing the file to premiere to double check, and yup, there it is. Then I stumble upon another one at about 15m 17s and starting at 1h 35m 23s the network source was seemingly completely lost, this time not displaying the classical "media offline" image but, maybe more appropriate for a cause as lost as this one, the color bar test image for the rest of the video with the file name of the PP Project displaying in the upper left corner, at which point I know for sure I will have to encode the whole thing all over again.

No errors were displayed by AME.

Now I would like to make sure that this does not happen again. I found and gladly checked the box "Don't encode sources containing offline media" in the Premiere Pro section of AME General Preferences and am hoping for the best and maybe some help from a fellow media encoder.

Why I would want to "encode sources containing offline media" in the first place is completely beyond me by the way, and why AME is seemingly, at least in my case, set do so by default even further out beyond. As I was exporting the file using AE I am wondering if there is an AE Preference setting hidden somewhere else which I need to watch out for or if anybody else was experiencing something along the same lines and found a way to reliably fix it.

All the software I was using to do this is up to date.

regards

philipp