UI Flickering on MCP Selection Menu

[josegtmonteiro]

What happened?

So basically what is happening is that when in the MCP selection menu for some of the MCP servers, we cannot activate it. When you click it, it does not stay marked. And that's not for all MCP servers, but for some of them. And what we also realize is that generally it might go away if you completely kill Google Chrome and get it back. But in some cases, even like opening incognito window and logging the same account, the same issue happens.

It is not something that happens all the time. It happens after a while and then you just can't select anything anymore. So it's a little bit hard to reproduce. But I have multiple users in my organization facing it frequently.

Kayako MCP server is one that has no user variables, Gmail and Google Drive are OAuth, GitHub is customUserVariable (PAT), so not much related to the authentication mechanism.

Issue persists also after reinitializing the MCP servers. No error on the logs (both librechat and MCP server logs).

The expectation was that the MCP Servers would stay selected.

Version Information

Running 0.8.0-rc2

ghcr.io/danny-avila/librechat latest f84d5bdccc27 9 days ago 1.16GB
ghcr.io/danny-avila/librechat-rag-api-dev-lite latest aa903ee07b4f 2 weeks ago 1.45GB
ghcr.io/danny-avila/librechat ec025d2f48db 2 weeks ago 1.16GB
ghcr.io/danny-avila/librechat 8f85fa0e8ad6 4 weeks ago 1.12GB
ghcr.io/danny-avila/librechat-rag-api-dev-lite 833a22bcf14c 6 weeks ago 1.45GB
ghcr.io/danny-avila/librechat 4b245c18cc8e 7 weeks ago 1.11GB

Steps to Reproduce

1. (After some time, or from time to time, not able to determine the Root Cause)
2. Open the MCP Server selection menu
3. Notice that, for some of the MCP servers, they don't stay selected

What browsers are you seeing the problem on?

Chrome

Relevant log output

No errors in browser console and nothing on debug and error logs

Screenshots

Code of Conduct

• I agree to follow this project's Code of Conduct

[danny-avila]

Update to the latest dev image, and let us know if you're still seeing the same behaviors.

Updating Instructions (docker):
https://www.librechat.ai/docs/local/docker#update-librechat

[josegtmonteiro]

This one, right?
https://github.com/danny-avila/LibreChat/pkgs/container/librechat-dev

In my local env, also not happening, we can only see it in our "prod" env deployed. In local env with same image it works well with the same MCP servers and under the same conditions.

I will also test if, on our "prod" env, once I get the problem, if restarting the LibreChat container makes any difference or not.

[danny-avila]

even as one MCP server is still initializing (paypal, since it uses OAuth discovery and is in-progress), I'm not experiencing the same issues:

[danny-avila]

also, be sure you see the "MCP servers initialized successfully" message in the server logs before trying to use MCP servers.

[josegtmonteiro]

@danny-avila , updated to rc3, and the problem is even more consistent now. Recorded this short loom demonstrating: https://www.loom.com/share/c6daba52ba124171bd6c51c021adae87

[josegtmonteiro]

And, as before, if you Quit chrome and open again, problem is solved.

[danny-avila]

Thanks, I think this might due to this PR based on timing of the original report: #8920

I'm not able to reproduce it reliably, but managed to do so earlier this week. Will poke around and will report back when it's live in case you experience it again.

[danny-avila]

Just merged PR #9324 which hopefully addresses the MCP UI flickering and selection persistence issues you described.

The changes fix:

• MCP selections clearing on page refresh by properly tracking initial load state
• Improper hook dependencies and near-circular dependency patterns
• Component re-rendering issues when conversation context changed

Since these were race conditions that couldn't be reliably reproduced, I can't guarantee 100% resolution, but the logic is much cleaner now and I feel much better about it. The root of these issues were caused by rapid development with different contributors working on related MCP areas in isolation, leading to conflicting logic patterns.

The updates should be live on librechat-dev image after this action completes:

• https://github.com/danny-avila/LibreChat/actions/runs/17286149381

[josegtmonteiro]

Thanks @danny-avila , will give it a try in the dev image and revert back if I can reliably say that it has been fixed (but can be hard as I couldn't identify how to trigger the issue consistently)

[genchmot]

I am encountering the same issue. Cleaning the storage and cache in the browser doesnt make it go away, not sure where it is stored. And its not returning any errors. But opening a private window or using another browser will make it go away.

[danny-avila]

Are you on latest?

Updating Instructions (docker):
https://www.librechat.ai/docs/local/docker#update-librechat

[genchmot]

yes I think so. Just updated yesteday. Also I found it only occurs when chat is empty, starting from a new chat. When I am in the middle of the chat I can click on the flickering mcp and its able to pick it up.

[danny-avila]

Follow the instructions to update since it will assure you use latest.

Since I can't reproduce this, I would recommend screen recording when this happens, viewing your browser console logs, as well as network logs if possible in the recording.

[danny-avila]

After managing to reproduce this, I figured out it was due to having multiple tabs/windows open, as the app will always try to sync with local storage, and there is a race condition between multiple instances. I will patch this soon and should still allow for individual selections between tabs

[josegtmonteiro]

Great, indeed it makes sense that closing all chrome or openning in a incognito solved the problem. Thanks @danny-avila . Do we expect the 0.8.0 soon? or will it be another rc before that?

[genchmot]

Yes, I found out that's the issue as well. When multiple tabs are open, the MCP flickers in one tab, and I can fix it by reinitializing it in the other tab.