Yes, I am able to reproduce this on Windows.
Adding a carriage return to any of the NLP fields will cause the export to not overwrite metadata. I would advise against using carriage returns in general, but I’ll patch this in next version.
This does NOT effect Mac users.
It’s just a peculiarity of the Windows environment 
Well that’s good at least it’s not an oddball one-off.
No, the carriage return was unintentional - likely just a result of my completing the field, or perhaps a copy/past remnant. But definitely seems like something that would easily rear its head on another users machine if they were not aware of this. (as I was not)
Paragraphs are friendly.
Here’s what I get on my iMac (2019 with macOS Mojave, Lr and NLP, each up-do-date)
When I right-click a bunch of NLP metadata enriched files to export as 16 bit TIFFs,
NLP metadata is NOT included in the exported files.
When I right-click a bunch of NLP metadata enriched files to send to external editor as 16 bit TIFFs,
NLP metadata is included in the exported files. -> This might be used as a workaround.
Are you using the Negative Lab Pro export presets? For instance, right-click on file > Export > NLP - Positive Copy - TIFF.
Is this what you are doing when you say you aren’t seeing the metadata? Or something else?
-Nate
@nate, I selected the first option of the list, not the one you highlighted.
Nevertheless, I wonder why normal export ignores nlp metadata while sending to an external editor does not.
I’m assuming the answer to this question is “yes”, but just for clarity, I’ll jump in as well.
After selecting the first context menu choice of “Export” (the first option on the list), did you then, on the following screen, select Negative Lab Pro in the “Export To:” drop down list at top, or one the NLP preset choices in the left-hand pane? e.g. did you get all the NLP export option dialogues shown?
Hmm… what exactly do you mean by “sending to an external editor?” Do you mean using the “Edit in” option to edit the file in another editor (like Adobe Photoshop)? And also, by NLP metadata, I assume you are referring to the custom Negative Lab Pro metadata section in Lightroom?
My experience has been that the “Edit in” option ALSO disregards the NLP metadata (at least in LR Classic 9.1).
It was actually pretty tricky to get the custom NLP metadata to be retained during export, and as far as I am aware, it requires using the custom export service I built (which forces the file to be immediately reimported so it can add the custom metadata back in to the catalog)
-Nate
Creator of Negative Lab Pro
This:
I can work the resulting (converted TIFF in DxO PhotoLab (shown above) and the re-export it from there. This workflow transmits at least some NLP metadata.
Interesting. When I try this in LR Classic 9.1 on a raw file (edit in > Adobe Photoshop), the resulting tiff copy that is created after editing in photoshop does NOT have the NLP metadata (nor would I expect it to).
If the file you are editing is already a tiff, and if using “edit in” is working against the original file, and not a copy, then in that scenario I would expect it to retain the NLP metadata.
…oops, I had some of the data in the keyword field, this is why I saw it in the file, sorry for the hiccup.
…does this imply that NLP metadata will be retained only if the enriched file is a tiff?
One more thing:
…just tried to export according to your screenshot above and get this message instead of an export:
Note that I had filled in all NLP metadata fields starting with “NLP-” (where possible) in order to more easily find entries in the output file - that was not created 
No… it just has to do with the way that Lightroom handles and stores custom metadata. The custom metadata in the NLP section is actually stored in the catalog itself and associated with the file (not embedded into file at that point). The included export service can do two things: 1) write the custom metadata into standard exif fields (which means it will use the custom metadata to write into standard fields) and 2) reimport the photo and re-associate it with the custom NLP metadata (as is done when you make a “positive copy”. Based on the options in the custom export service, you can determine which of these things it does, it how it does them.
Yeah, that could cause of problem. The fields are expected to be using standard notation. For instance, the focal length should be something like “80mm” and not “nlp-80mm”, because it is using that to calculate the “35mm Equivalent” tag, just as an example.
Also, make sure you are on the latest version of NLP (v2.1.2) and Lightroom.
Thank you, @nate, for the illumination. And yes, I use the latest versions of NLP and Lr Classic.
Nate, any fix yet for this? What might be the timeline here?
Hi Nate,
I have scanned this lengthy exchange, but none of the suggestions have solved my problem. Here it is in brief:
Why is this important? I just converted 900 negatives and used “Shooting Notes” to insert a caption in each and every one.
It is horrifying to me to think that all these captions have been lost on the way to the TIF.
Can you help?
Thanks
Ami
Hi,
If you would like to have a written caption on the exported photo, that best place to put that is in the regular “Caption” field in Lightroom. (You can enter it in the “Default” metadata section, or the “Large Caption” section.)
Then when you export, you can choose the “Append Caption” if you want your caption to be retained, and the “Auto-Caption” added to it.
If you wrote captions for all of your images, but placed them in the “Shooting Notes” section, you should be able to go back to the original RAWs and just move the descriptions from Shooting Notes over to the Caption. There are plugins that can make this quick and easy to do in bulk, like this one: https://www.photographers-toolbox.com/products/jbeardsworth/findreplace/index.php
Let me know if that helps!
-Nate
HI Nate.
Many thanks for the quick response.
When I entered my captions into the “Shooting Notes” field I didn’t realize that this field will not get into the TIF file, but I knew that it will not show in the description field in, say, Mac Photos. It was just convenient to access this field, and I was planning on using Phil Harvey’s Exiftool to do copying en messe.
I guess I will have to do cut and paste. At 20 seconds each, I am looking into 5 hours of drudgery 
I’ll check out the plugin.
While we are on the subject of meta-data, I have a minor request:
Can you add other film formats, such as 110 and 126 – for those digitizing ancient negatives?
Many thanks!
Ami
There are scripts in the (deprecated but available) Media Pro that will copy or move metadata from one field to another.
Hi again,
I am trying to transfer meta-data (from Shooting Notes to Caption) using the plugin you suggested
https://www.photographers-toolbox.com/products/jbeardsworth/findreplace/index.php
The problem is that the plugin doesn’t find the field Shooting Notes.
Any suggestion?
Thanks
Ami
I always though that NLP metadata are embedded into DNG. Now I see it’s only in the file that you export using NLP export presets, right?
