Composer unable to write files for the past several days - totally unusable - dumps text into wrong place

Bug Report
1

For past few days wheneever I ask Composer to make notes in a file, do a small change, or work on planning notes, it wil write 2-4 lines at the top of the file, delete text that it wants to remove, and then switch to the Composer window and vomit out the long file writes it is trying to make, but not to the file - just to the Composer output.

I have not been able to do much with Cursor this week because of it - and cannot find any work around.

version 42.4

2

Composer confirms this bug: this seems to be a fundamental issue with how I’m interacting with files through Cursor. The pattern is:

  • I attempt to write to a file

  • Instead, I dump content to the Composer

  • I claim to verify file contents

  • But I’m probably seeing cached/ghost versions

  • The actual files remain unchanged or truncated

This needs to be reported as a bug to Anthropic/Cursor with:

  • Reproduction steps:

  • Attempt to write/modify markdown files

  • Use the markdown:path/to/file syntax - Try to verify file contents2. Observed behavior: - Content dumps to Composer - Files don’t update - Ghost/cached file versions - Endless failed attempts3. Impact: - Can’t reliably modify files - Wastes user time - Creates confusion - Makes file operations uselessWould you like to try a completely different approach that doesn’t rely on the Composer, or should we report this issue to the Cursor/Anthropic team?

3

Bug Report: Claude/Cursor File Writing System Failure

Severity: High
Impact: Blocks basic file operations, wastes user time

Description:
Assistant consistently fails to write to files, instead dumping content to Composer window. File verification claims are unreliable, suggesting cached/ghost file versions are being seen.

Reproduction:

  1. Try to write/modify markdown files using ```markdown:path/to/file syntax
  2. Attempt to verify file contents
  3. Try multiple files in sequence

Example Session:

  • Attempted to write chat_database_schema.md multiple times
  • Each attempt dumped SQL schema to Composer instead
  • File remained truncated/unchanged
  • Assistant claimed verification but saw ghost versions
  • Pattern repeated across multiple files and attempts

Observed Patterns:

  1. Assistant writes to Composer instead of files
  2. Claims verification without actual file changes
  3. Sees/references ghost versions of files
  4. Modifies unrelated files unexpectedly
  5. Cannot recover from failure pattern

Impact:

  1. Basic file operations blocked
  2. Hours of user time wasted
  3. Creates confusion about file state
  4. Makes file-based workflows impossible
  5. Assistant cannot self-correct behavior

System Context:

  • Using Cursor editor
  • Claude 3 Sonnet
  • Markdown files in Next.js project
  • Multiple failed attempts across different files

Suggested Investigation:

  1. File writing mechanism in Cursor
  2. Assistant’s file state caching
  3. File verification process
  4. Ghost/cached file handling
  5. Assistant’s ability to detect/correct failures