Language Picker does not update Content Tree

[tsmithdk]

Which Umbraco version are you using?

16.1.1

Bug summary

When a new language is selected from the language picker above the Content Tree. The Content Tree is not updated. Reloading the page does not work. Clicking on a specific node updates that node only to show the correct content based on language.

Specifics

This bug is consistent in Firefox.
In Chrome the bug persists but not consistently. It varies depending on internet speed it seems but not sure.

Steps to reproduce

After changing language you can see the selected language is Danish but the Content Tree shows the Home Page for EN-US

After clicking on the node Home page (EN-US) in the content tree you can see the content changes which matches the selected language

Expected result / actual result

That the content tree changes as soon as a new language has been selected

[github-actions]

Hi there @tsmithdk!

Firstly, a big thank you for raising this issue. Every piece of feedback we receive helps us to make Umbraco better.

We really appreciate your patience while we wait for our team to have a look at this but we wanted to let you know that we see this and share with you the plan for what comes next.

• We'll assess whether this issue relates to something that has already been fixed in a later version of the release that it has been raised for.
• If it's a bug, is it related to a release that we are actively supporting or is it related to a release that's in the end-of-life or security-only phase?
• We'll replicate the issue to ensure that the problem is as described.
• We'll decide whether the behavior is an issue or if the behavior is intended.

We wish we could work with everyone directly and assess your issue immediately but we're in the fortunate position of having lots of contributions to work with and only a few humans who are able to do it. We are making progress though and in the meantime, we will keep you in the loop and let you know when we have any questions.

Thanks, from your friendly Umbraco GitHub bot 🤖 🙂

[NguyenThuyLan]

Hi @tsmithdk , thank you for reporting the issue.
However, I tried to reproduce it on Firefox like this below video (v16.1.1), but it still runs correctly
https://github.com/user-attachments/assets/889aecd5-36f9-4267-a0cd-3563046fc9dd

[tsmithdk]

Hi @NguyenThuyLan it seems the error only occurs when running Umbraco Cloud with Umbraco Deploy. When I comment these packages in .csproj, the language selector works

Maybe it is related to this issue?
umbraco/Umbraco.Cloud.Issues#942

So if you have those 2 packages you should be able to reproduce the error in firefox?

[ronaldbarendse]

I've tested Deploy 16.0.0 and can confirm this is a regression introduced in CMS 16.1.0 (this doesn't happen on CMS 16.0.0), most likely in PR umbraco/Umbraco-CMS#19292. @madsrasmussen Do you have an idea whether this could be the cause?

It doesn't always occur, but seems to be more likely the more entity actions are registered (which explains why Deploy makes the issue visible, since it adds the 'Queue for transfer', 'Partial restore' and 'Export' actions). Refreshing with the browser cache disabled also increases the times it occurs, so together with the initial finding about inconsistency based on internet speed, this would indicate some kind of race-condition/timing issue.

[umbracocommunity]

This issue has been mentioned on Umbraco community forum. There might be relevant details there:

https://forum.umbraco.com/t/umbraco-backoffice-icons-not-loading-properly/4958/2

[nielslyngsoe]

Hi @ronaldbarendse, just adding a few thoughts on this issue for you or who comes later to look into it :-)

This seems very related to this issue umbraco/Umbraco-CMS#18083

And I do notice all reports have been on Umbraco Cloud, so I think that needs to be taken into account.
As well, it may explain why @NguyenThuyLan hasn't been able to reproduce it.

I think we need to look closer into the network requests to understand what goes on here.

[madsrasmussen]

Hi,

I have been digging a bit, and I have found out that Deploy registers a tree item that somehow prevents the Document tree item from core from being loaded. See the video below where I unregister the Deploy tree item, and then the Document tree item works again.

I forgot to include the language picker in the video, but it works too :)

Screen.Recording.2025-08-07.at.15.34.04.mov

[AndyButland]

Just for reference, here's where core's document tree is registered.

There are differences, but don't know if there's anything significant there.

Could it be though that the backoffice doesn't like having two tree items registered for the same entity type?

If so:

• Does core need to support a forTree when registering treeItem types? These have a forEntityTypes to link them to an entity type, but not to a specific tree.
• Or does Deploy need to register it's own entity type for "remote documents"?

[madsrasmussen]

The Backoffice doesn't like having two Tree Items registered for the same entity. Currently, it looks like a race condition on which one loads first. We could handle this more gracefully and throw an error.

If Deploy is interested in replacing the Document Tree Item from core, they should either prevent our registration or use the overwrite feature in the manifest. https://docs.umbraco.com/umbraco-cms/customizing/extending-overview/extension-registry/replace-exclude-or-unregister

Based on the name "Remote Document Tree Item", it doesn't sound like that is what we are trying to achieve. I think the best solution would be to use its own Entity Type: Ex: "deploy-remote-document." This way, they also won't inherit all our entity actions that are bound to a Document entity. I assume it shouldn't be possible to create, delete, reorder, etc., on a remote tree.

[AndyButland]

@nathanwoulfe @ronaldbarendse - how does the above suggestion form Mads sound? Seems like it would be the best solution here. He's correct on what the "remote document tree" is for in Deploy, i.e. just picking, not for triggering operations on. If you agree, I'll move this to the Deploy tracker.

@madsrasmussen - does sound like it would be a good idea though to detect if there's >1 tree item registered for the same entity, and throw an error, as a race condition is always a tricky one to debug.

[nathanwoulfe]

It's been a hot minute since I've looked at Deploy UI, so need to have a look at how we use that tree item - if it's only for building picker trees, then the entity type shouldn't matter, we're only interested in the unique.

I'll move this to the Deploy tracker.