Lightbox not working on Discourse


I recently set up a Discourse forum using the Marketplace Linode, and for some reason, the images are not clickable, meaning that the Lightbox is not working as intended.

To be more specific: I am expecting to click on an image, and the image to be enlarged and displayed in the gallery, how it works on the official Discourse. Here is an example: Better Discourse Lightbox - #2 by codinghorror

Here is the link to the forum, where you can test the images:

This is how Sidekiq looks:

Can you please assist? Is there something I need to do to enable this functionality?


We can only support the official install process here as we can’t speak to the different variables in other install modules. If you can, try reinstalling using the official install process and see if this is an issue.

As a general tip though, try making sure you are updated to the latest Discourse version, see Latest release-notes topics - Discourse Meta for the latest, and see if the issue persists. If the issue persists, try using safe mode to rule out possible theme or plugin issues that may be causing the issue.

That said, we can only support the official install here.


I contacted Linode, they told me to contact Discourse for help.
I contacted Discourse trough this forum, and you guys are recommending me to install the official version.
In this case, we shouldn’t use any marketplace app?

I tried safe mode and that did not help. Isn’t there any way to check what happens with Lightbox and why doesn’t that work? From what I can see, this issue happened for other people, and it was not solved.


I also gave you other solutions to try though: :wink:

We encourage people to use any hosting service they like, but after development and testing, we found Digital Ocean’s droplets to give the least amount of issues and so over the years we’ve recommended and used them. With Digital Ocean, we are aware of how it is set up and how it works and what the possible issues are, but with other hosting services and marketplaces, we aren’t as we don’t have any visibility into how they set up their installation process.

We’d like to help with this, so we created a standard install process so if anyone follows this process, we know what to expect and what possible issues are. Outside this, it is near impossible to speak to what the possible issues are, as there are so many variables involved.

That said, please be aware that Discourse is free and open source and so you are free to use it as you like or install it where you like. We can also give you free support for your Discourse instance via this community if you use our standard install. If this support process isn’t favourable, we created a #marketplace where you can pay for support and one of our many experts will handhold you through the process.

Thank you for your kind words and consideration :slight_smile:


Thank you. But the solution does not work. I already have the latest version of Discourse and safe mode doesn’t help.

I understand your position, and I understand that the product is open source. This is one of the reasons I chose it. But what I’m looking for is for some kind of documentation, or points to look for in order to solve the Lightbox issue.

I didn’t know about the Marketplace and I will probably give it a go if I can’t find a solution. But this feels like a free to use app with paid support. Nothing wrong with that, if this would be known from the start :smile:

Either way, thanks for your time. I’ll wait a bit longer.
Maybe there’s other tips from other users about what check in order to solve this.


Support is free too depending on how you install it :wink: :point_right:t5: standard install :wink:

I’ll suggest doing a test. Have you tried posting the same images on other Discourse forums? You can use our demo site for tests like this: or create a trial site on any of the other Discourse hosters to see if this issue persists.

It may be that you’ve discovered a bug and I answered you wrongly, so try to test it and see.


I have been testing this. :raised_hand_with_fingers_splayed::slightly_smiling_face:

The images I grabbed from the example topic in the OP work fine on my test site, but comparing the code in the browser inspector, mine get a lightbox-wrapper and @3DPB’s do not. I’ve tried tweaking a few settings, but no effect so far.

You could check your create thumbnails and composer media optimization image enabled admin settings, just to be sure (and confirm that we have a similar set up for any tests :slightly_smiling_face:)

The only other topic I could find with a similar issue is this one, but the solution was to dial up a new instance which magically fixed it, so the same solution that’s been offered already.

So far, it’s quite a frustrating problem to replicate/solve. :slightly_smiling_face:


I can confirm that the create thumbnails and composer media optimization image options are enabled.

Could it be something related to the values used there?


I doubt it, those are the default values so they should work. Our suggestion is still to reinstall and restore a full backup :wink:


I’m also experiencing the same problem: unfortunately lightbox is not working on our discourse installation (even in safe mode).

I also stepped into a similar report from another user here: Image Lightbox not working from start .

Any idea on how to debug this problem?

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How did you install this Discourse instance?

I went for the official/docker installation.

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@osioke any idea or suggestion on how I could try to solve the lightbox not working problem?
thank you!

We’ve seen this happen intermittently and we are looking at what could be the cause. We need a consistent reproduction of this scenario more than once with steps one can follow, so we can find a fix for it. So far we haven’t been able to do this.

For a quick fix, would you mind taking a full backup of your instance, reinstalling your instance following the standard install and restoring the full backup? That always seems to resolve the issue.

We will keep looking at this though.

@osioke thank you very much for your reply!
It’s not easy for us to bring the forum down and reinstall everything but we might be able to do during the planned maintenance in a couple of weeks.

Just a suggestion from your side: are we sure that a fresh install + restoring the backup is completely safe and could not break other stuff? We just wouldn’t like to trigger bigger issues by trying to get lightbox working - I’ve just noticed that it’s not working myself, nobody really complained about it so I kind of consider a minor issue.
Thank you!

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If it is done well, it should not break any other stuff.

Oh, I see. Then I’d say be patient and do not post on multiple topics as that creates the impression it is a big issue.

I think that this last comment of yours was unnecessary.

It doesn´t look to me that I could appear impatient or pushy.
I’ve just posted a reply on this thread and here to notify the user who posted, that was asking for help, that there was a thread already opened here.
But apparently there was at least another post about the same issue here. So I guess it’s not me, maybe these posts may get combined and in any case I don’t see any problem in referencing other posts about the same topics as a reply.

I evaluate the job you developers are doing and I believe I’ve tried to be thankful while writing my messages. But being part of the team should not allow anyone to be rude, but please let’s not start a flame.