Where does the bug appear (feature/product)? Cursor IDE Describe the Bug Since the update this morning, I’ve been getting this error frequently. I changed everything to auto, not requesting any web searches or tool calls. I had some prompts work, and some fail. Turned off my MCP servers, same resul…

Hi there! This error indicates that a sessionStart hook is failing—the hook is calling an external service that’s returning a 400 error. Quick fix: Locate and temporarily remove or rename your hooks.json file from one of these locations: ~/.cursor/hooks.json (user-level) <project>/.cursor/hooks.…

Hey Colin, thanks for your reply! Neither file exists, I haven’t set up any hooks.

Thanks @JulianKingman ! There might be a few other places to look. Check if you have ~/.claude/settings.json or <project>/.claude/settings.json files that might contain hooks Claude plugins: Check ~/.claude/plugins/ for any installed plugins Do you see any configured hooks under Cursor Settings > …

Why is cursor suddenly looking at ~/.claude/ config files even if I’m not using any anthropic models?

Thanks @Joshua_Buss , that was why it was failing for me! Also no Cursor hooks, but my .claude settings had an “enabledPlugins” that caused this for me.

Should I uninstall all plugins? I’ve got claudmem and context7 plugins installed. No hooks set up anywhere, in .claude nor .cursor

[image] Joshua Buss: Why is cursor suddenly looking at ~/.claude/ config files even if I’m not using any anthropic models? You can turn this off under Cursor Settings > Rules, Skills, Subagents [Screenshot 2026-01-31 at 09.57.54] @JulianKingman As a troubleshooting step, you might try swit…

Yep, disabling those solves the issue.

I’m hitting the same issue that’s completely blocking me from using Cursor. This started right after I updated to version 2.4.27 on macOS ARM64. The error I’m getting is: “Hook blocked with message: Hook error: Error: Session initialization failed: 400” When I check the Hooks logs and try to run t…

Hey @Maxim_B When you disable this: [image] Colin: [Screenshot 2026-01-31 at 09.57.54] You’re only disabling the use of third-party skills (like those in a .claude directory) [image] Maxim B: Why is Cursor now forcing Claude Code initialization even when it’s not being actively used? …

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Support Bug Reports

Topic		Replies	Views
Submission blocked by hook - ERROR_HOOKS_BLOCKED (Session initialization failed: 400) Bug Reports hooks	4	758	April 7, 2026
Claude Code project hooks (.claude/settings.json) are no longer run (3.24.9) Bug Reports devcontainers , hooks , agents-window	4	114	October 12, 2026
Duplicate notifications when using Claude hooks alongside Cursor Bug Reports hooks , composer	2	153	April 19, 2026
beforeSubmitPrompt does not wait for the hook: a block returned after ~1 second is ignored and the prompt is sent Bug Reports hooks	3	70	October 17, 2026
[REGRESSION] Hook response fields user_message / agent_message still ignored in Windows v2.0.77 Bug Reports	10	340	December 20, 2025

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