I keep getting tool call error for every prompt

[MJHNJ]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

every prompt results in a ‘tool call error’ message

Steps to Reproduce

enter any prompt and this error is returned. the session was working normally for 50 mins before this occurred

Expected Behavior

prompts work

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.0.77
VSCode: 1.99.3

For AI issues: which model did you use?

Sonnet 4.5

Additional Information

the session had been working normally before this and no issues prior to this

Does this stop you from using Cursor

Yes - Cursor is unusable

[deanrie]

Hey, thanks for the report. “Tool call error” messages can appear for a few different reasons, so let’s go through some steps to narrow it down.

First, try these quick checks:

• Create a new chat and see if the error still occurs there (this can help if the state of a specific chat is corrupted)
• Check if you have any MCP servers configured in Settings → Cursor Settings → Tools & MCP, and if so, try temporarily disabling them
• Run network diagnostics: Cursor Settings → Network → Run Diagnostics

If the issue persists, please share:

• Request ID: chat menu (top right) → Copy Request ID
• A screenshot of the exact error message
• Whether you have any MCP servers configured
• The results from the network diagnostics
• Which mode you’re using when this happens?

This will help us understand whether this is a new bug or a configuration issue. Let me know what you’re able to collect.