jf Collection Publisher "Photos with original missing"

I suspect that the issue presented by the OP is not caused by LR considering some photos and videos to be "missing" as LR uses the term (that is, a photo or video in the catalog but whose link to an actual file has broken). I'll bet that if the OP uses the LR interface to search for missing photos, that none will be found (or at least not the ones that are listed in the error message). 

I ran into the same issue, and after a lot of sleuthing, I believe that the problem only occurs if the Publish Service used has a post process action active.  I wrote this up on this board here. 

I suggest that the OP check to see if they have a post-process action installed and "inserted" into the jf Collection Publisher service. If so, try clicking "remove" and see if that solves the issue. IMPORTANT: Click "Remove" at the bottom, to the right of "Insert"!  Do NOT click the "Remove" button to the right of the "Add" button!

I think this is a continuation of the bug that was introduced when version 13 first came out. The initial bug was that post process actions did not fire at all. Adobe fixed that, but then the issue was that publishing photos and videos would fail if there was an unpublished video (or a video needing republishing) in the service. Now videos will publish (and republish), but NOT if there is a post process action present and inserted.