Error Exporting

I just filled in a bunch of NLP specific metadata and went to export my images (making TIFFs). It hangs for a bit and then fails with message:

Unable to Export

An internal error has occurred: Exif.lua:30: attempt to perform arithmetic on local ‘n’ (a nil value)

I receive the message from the export option in the NLP window and the standard export dialog.

I suppose I will try deleting each piece of metadata looking for a trigger. This really seems like a bug.


Let’s see if we can figure out what is going on…

  • What version of Negative Lab Pro are you on?
  • What version of Lightroom specifically?
  • Windows or Mac?
  • Can you share a screenshot of the Negative Lab Pro custom metadata you have entered?


NLP is 2.1.2
Lightroom Classic 9.3
MAC macOS 10.15.6

When I delete the Shooting information everything works. It’s not exactly important information as I have absolutely no idea of the settings or even the lens used on my 19 year old shots. But, I figures I should report the issue.

Ahh, yeah, it expects certain types of information to be in those metadata fields (or to just be left empty). The full documentation on this is being added to the official guide, and I’ll include more info on the fields and what values are acceptable.