LrC Export to Helicon Focus Plugin fails

[Pieter Noordzij]

Issue: LrC Export DNG (or Tiff) file(s) to Helicon Focus Plugin fails

• Lightroom Classic Version Number: 11.5
• Camera Raw version number: 14.5
• OS Version Number: MacOs 12.6

Steps to reproduce:

1. Select several images in the library module
2. Go to Export -> Helicon Focus (DNG)

Expected result:

DNG files are created, Helicon Focus is launched, DNG files are read / processed by Helicon focus.

Actual result: 

DNG files are created in "private/var/folders/kg/T/...."

After the last file is created Helicon focus is launched.

As soon as Helicon Focus gets launched, all de DNG Files are deleted.

If the Helicon Focus app is deleted (so it won't start) the DNG files are still created upon export but are also deleted when LrC tries to launch Helicon Focus.

If I stop LrC before the last DNG file is created upon export, the DNG files do exist in the folder:"private/var/folders/kg/T/...."

So the DNG files are created as expected but deleted too early before Helicon Focus can handle them.

Did reset LrC settings, did reinstal LrC.  Same result.

[GoldingD]

In LrC, in the plugin manager, does the plugin in question show any error messages, does it indicate an update exists?

Maybe the plugin needs to be replaced, see:

https://www.heliconsoft.com/faq-helicon-focus/

[Pieter Noordzij]

Thanks for your reply.
I have had extensive contact with Heliconsoft. Tried even a special version with extended logging to resolve this issue.

Helicon focus is reporting that the DNG files are missing and that is correct because they are missing at the time Helicon Focus want to access the files.
It is clear that it is not Helicon Focus that is deleting the files.

[JohanElzenga]

I have the same setup and everything works as expected for me. Does Lightroom have Full Disk Access? Apple changed the security requirements in MacOS Monterey. Go to MacOS 'System Settings - Security & Privacy' and add Lightroom Classic to "Full Disk Access". Click on the lock icon to unlock the settings, then click on the plus icon to add Lightroom Classic if it isn't already listed. If it is listed, then just enable the checkbox. Maybe add HeliconFocus too to be sure. See also Quick Tips: How to give Full Disk Access to Lightroom Classic on macOS

[Pieter Noordzij]

Thank you for your reply.

The Full Disk Acces was not assigned in the way that you decribe. So I dis that for LrC, Ps an HF as well.

Still the same result unfortunately. 

I am wondering how it should noramlly work... Who is it to delete the files if everything works as expected. Should it be LrC or HF or even maybe macOS?

If I stop LrC while exporting is still busy, then the files are there where they should be. In that "private/var/folders/kg...." folder. But when I the reboot my Mac the files are gone. So Who does delete them, at what point, and why?

[JohanElzenga]

"Private/var/..." is a MacOS system folder. I'm not sure if that is where the DNG files should go in the first place, and I can't check what happens on my system because I type this on my iPad. I know HeliconFocus works correctly on my system because I tried if very recently. I think this system folder is for temporary files, and in that case it's fine and it's MacOS that deletes them if they are no longer in use.

[Pieter Noordzij]

Thank you for your reply.

I found out that the folder where LrC export the DNG file is the macOS temp folder.

If I enter the command "echo $TMPDIR" in terminal it is returning the exact locatien where LrC exports its DNG files to. '/var/folders/kg/_0f14sr140nd4v16kr2srkww0000gn/T/'

Helicon Focus is returning an error: Load image error: No such file or directory '

/var/folders/kg/_0f14sr140nd4v16kr2srkww0000gn/T/.....'

which is the correct macOS temporary folder and the DNG files where there but disappeared just before HF is launched.

Pieter Noordzij

[Pieter Noordzij · Accepted solution]

Today I found a solution to the problem myself.

In the macOS temporary folder, which is the default folder for Helicon Exports, I created a new folder called 'HeliconFocus'.

Then in the Helicon Focus preferences under the setting 'Disk cache foler' I pointed to the new created folder.

And now it works like a charm!

If I set it back to the (original) temporary folder, the error returns.

[JohanElzenga]

Interesting. If I check what folder is set, it is /var/folders/75/4pkf209m8xjbtb001s70xl600000gn/T/Helicon. So indeed, there is a subfolder by default.

[Pieter Noordzij]

Hi Johan

That's interesting indeed. 
Anyway, thank you for your support and time. Very much appreciated. 

Pieter Noordzij

[heffSTL]

This problem is still around in 2025 and I've got an actual working solution for anybody still dealing with this..

The issue is that the LrC plugin installed by Helicon has the wrong path for the application. So round tripping to Helicon Focus from Lightroom will fail every time becaue the app isn't where the plugin is expecting to find it.

The solution is to find the HeliconFocus.lrplugin (mine was in ~/Library/Application Support/Adobe/Lightroom/Modules) and right click on the plugin to Show Package Contents.

Inside you will find a simple text file called HeliconFocusPath.txt which contains the actual path to the App.

Open that file with TextEdit (or app of your choosing) and replace the app path with the correct one.

The path to the app will be completely wrong (it will be a random /var translocation folder) and needs to be replaced with: 

/Applications/HeliconFocus.app/Contents/MacOS/HeliconFocus

Save the text file and close the plugin folder.

In Lightroom Classic, go to the plugin manager, find the Helicon Focus plugin and reload it to pick up the change you made.

Now the round-trip function will work as it should!

[Thibaut17277902pamo]

Hello and thank you for your advice

I recently had a related but slightly different problem:

I'm on a Mac (Ventura) and I have the latest version of Helicon as of today.

When I export from lightroom-cc to helicon, helicon doesn't launch. But when I quit Lightroomcc, Helicon launches as standard, loading the previously exported images... (If I reopen Lightroom afterwards, of course the images from Helicon's processing don't appear).

I can still use Helicon as a solo application, but it's annoying.

I've tried everything to solve the problem (cache path, plugin path, reinstall helicon, lightroom), nothing fixes the problem. even Helicon is scratching its head. If anyone has a solution, it's most welcome.

[heffSTL]

As far as I understand, the Helicon Focus plugin is for Lightroom Classic and not Lightroom CC (desktop/cloud/etc) That might be where you are getting tripped up. Can you confirm that you are working with Classic?

[Thibaut17277902pamo]

... Yes, sorry, I should have written ‘Lightroom classic’ instead of cc. But I'm in the Classic version.