Claude Code LSP Broken: A Deep Dive Into The Bug

Current Status: BROKEN

The Julia LSP plugin, and by extension all LSP plugins, are currently non-functional. This frustrating situation stems from upstream bugs within Claude Code itself. For those of you relying on the Language Server Protocol (LSP) for enhanced coding experiences, like intelligent code completion, error highlighting, and navigation, this means a significant disruption to your workflow. We understand how critical these tools are for productivity, and we're working to get them back online as quickly as possible. The impact is widespread, affecting anyone who uses the latest versions of Claude Code and has LSP-enabled plugins configured. This isn't just a minor inconvenience; it's a complete roadblock for features that many developers consider essential for modern software development. We're tracking the situation closely and will provide updates as they become available. The core issue lies within the foundational components of Claude Code, which is why the fix needs to come from the upstream developers.

Root Cause: A Race Condition in Claude Code's LSP Initialization

At the heart of the problem lies a race condition in Claude Code's LSP initialization, specifically detailed in Issue #13952. To break this down, imagine a sequence of events that need to happen in a specific order for everything to work correctly. In this case, the LSP Manager, which is responsible for coordinating all Language Server Protocol functionalities, is starting up before the plugins that rely on it have finished loading. This premature initialization means that when the LSP Manager completes its startup process, it registers zero servers. It's like trying to start a car before all the necessary parts are in place; it simply won't run. Approximately 52 milliseconds later, the plugins finally load and are ready to go. However, by this point, it's too late. The LSP Manager has already finished its initialization with an empty server list, and it's no longer looking for new servers to register. This timing mismatch is the critical flaw. For developers, this translates to LSP features simply not activating, leaving you without the powerful assistance these tools are designed to provide. Understanding this race condition is key to grasping why the fix needs to originate from the Claude Code development team, as it's a problem with the core architecture of how the application handles plugin and LSP initialization.

Related Upstream Issues: Understanding the Bug Reports

To get a clearer picture of the ongoing efforts, it's helpful to look at the specific bug reports that detail this problem. The primary issue causing the widespread LSP malfunction is Issue #13952, titled "LSP servers not loading due to race condition." This is an Open issue with a significant amount of attention, indicated by over 46 reactions, showing just how many users are affected and eager for a resolution. This is where the core of the race condition is being discussed and where potential fixes will be implemented. Complementing this is Issue #14803, titled "LSP plugins not recognized despite correct configuration." While this issue is marked as Closed, it likely represents earlier manifestations or related symptoms of the same underlying problem that were addressed or have evolved into the current, more critical race condition. Tracking these issues provides transparency into the development process and highlights the community's involvement. The high number of reactions on #13952 underscores the urgency and the impact this bug is having on developers who rely on robust LSP functionality for their daily coding tasks. It’s a testament to the community’s active participation in identifying and resolving critical issues within the development environment.

Affected Versions: Pinpointing the Problematic Releases

Identifying the exact versions of Claude Code that are experiencing this LSP breakdown is crucial for users to understand if they are impacted and what actions they might need to take. Our investigation shows that Claude Code version 2.0.69 and any subsequent versions are currently BROKEN concerning LSP functionality. This means if you have updated to this version or later, you will likely encounter the non-functional LSP plugins. On the other hand, Claude Code version 2.0.67 is confirmed to be WORKING. This provides a clear demarcation point. If you are currently using version 2.0.67 or an earlier working version, your LSP plugins should remain functional. However, the moment you update to 2.0.69 or beyond, you'll likely experience the issue. This information is vital for troubleshooting and for deciding whether to postpone an update or implement a workaround. Knowing these specific version numbers helps isolate the problem and confirm that it's indeed an upstream issue introduced in a recent release of Claude Code, rather than a problem with individual plugin configurations.

Workaround: Downgrading to a Stable Version

Given that the latest versions of Claude Code are currently broken, the most immediate and effective workaround is to downgrade to Claude Code version 2.0.67. This version has been confirmed to work correctly with LSP plugins. The process for downgrading will depend on how you initially installed Claude Code. For users who installed via npm, the command would typically be npm install -g @anthropic-ai/claude-code@2.0.67. If you used Homebrew, you would use brew install claude-code@2.0.67. It's essential to check your current version first by running claude --version in your terminal to confirm which version you have installed. Please be aware that downgrading means you will be using an older version of the software, and as such, you may lose access to newer features or security updates that have been introduced in versions 2.0.69 and above. Therefore, use this workaround at your own discretion, weighing the immediate need for functional LSP against the potential drawbacks of running an older version. We recommend reverting to the stable version until an official fix is released by the Claude Code team.

How You Can Help: Contributing to the Solution

While the ultimate fix for the broken LSP functionality lies with the Claude Code development team, the community can play a vital role in accelerating the resolution. There are several ways you can contribute. Firstly, upvote the upstream issues, particularly Issue #13952, by giving them a thumbs-up reaction on GitHub. This helps signal the severity and widespread impact of the bug to the developers. Secondly, if you can reliably reproduce the race condition or have any insights that might aid debugging, provide debugging information in the relevant GitHub issue threads. Your logs or detailed steps to reproduce can be invaluable. Thirdly, as the Claude Code team releases patches or experimental fixes, test proposed solutions and report your findings. Community testing is crucial for verifying that a fix works across different environments. Finally, if you discover any alternative workarounds that help you or others maintain productivity, share them within this discussion or on the relevant GitHub issues. Every bit of help, from a simple upvote to detailed bug reports, contributes to getting LSP functionality restored faster.

Timeline: The Path to Resolution

The resolution timeline for this critical issue is entirely dependent on the Claude Code development team addressing and implementing fixes for the upstream bugs we’ve discussed, primarily the race condition in LSP initialization. We are actively monitoring the situation and will provide updates as soon as we have concrete information. This includes notifying the community once a fix is confirmed and integrated into a new release, at which point we will update this report and remove any warning messages. Our priority is to ensure that LSP functionality is fully restored and stable before we declare the issue resolved. We understand the disruption this causes and appreciate your patience as we await the upstream fix. Rest assured, we are committed to keeping you informed every step of the way. Until then, the recommended workaround remains downgrading to a previously stable version of Claude Code. We will be watching the GitHub repository for Claude Code for any updates on the relevant issues.