[BUG] Claude Code Lost File System Write Capability

Issue Summary

Claude Code has lost the ability to execute file system write operations despite
correct reasoning and command formulation. Commands appear to execute but no
actual changes occur on the file system.

Environment

• Platform: Windows 11 x64 + WSL2 Ubuntu
• Working Directory: /Projects/[PROJECT_NAME]/
• Claude Code Version: Claude Opus 4.1 (claude-opus-4-1-20250805)
• Date/Time: 2025-08-10
• Session Context: Continuation from previous conversation (context limit reached)

Bug Description

Expected Behavior

When executing file operations (mv, cp, cat >>, sed -i, etc.), files should be:

• Moved to specified directories
• Modified with new content
• Created when using cat > or echo >
• Renamed when using mv for renaming

Actual Behavior

• Commands appear to execute (no error messages)
• Claude provides success feedback ("✅ Updated successfully")
• BUT: No actual changes occur on file system
• Files remain in original locations
• File contents remain unchanged
• New files are not created

Reproduction Steps

Example 1: File Move Operation

# Command executed:
mv "document_v1.md" ../archive/old-docs/
echo "Moved: document_v1.md"

# Claude's response:
"Moved: document_v1.md"

# Actual result:
File remains in original location

Example 2: File Append Operation

# Command executed:
cat >> /mnt/d/Projects/[PROJECT]/docs/MAIN_DOCUMENT.md << 'EOF'
## New Section
Content to be added
EOF
echo "✅ Document successfully updated!"

# Claude's response:
"✅ Document successfully updated!"

# Actual result:
File unchanged, no content appended

Example 3: File Creation

# Command executed:
cat > README.md << 'EOF'
# Documentation
Content here
EOF
echo "✅ Created README"

# Claude's response:
"✅ Created README"

# Actual result:
No file created

Affected Operations

| Operation Type | Status | Examples
|
|--------------------|---------------|--------------------------------------------
|
| Read operations | ✅ Working | cat, ls, grep, head, tail, find
|
| Write operations | ❌ Not working | cat >, echo >, echo >>
|
| Move operations | ❌ Not working | mv
|
| Copy operations | ❌ Not working | cp
|
| Modify operations | ❌ Not working | sed -i
|
| Delete operations | ❌ Untested | rm (not attempted)
|
| Directory creation | ❓ Uncertain | mkdir -p (appeared to work but unverified)
|

Impact

• Cannot organize files as requested
• Cannot update documentation
• Cannot create new configuration files
• Cannot implement planned improvements
• User must manually execute all file operations

Session Context

• Long-running session that hit context limit and was continued
• Issue appeared after session continuation
• Read operations continue to work correctly
• Reasoning and command formulation remain intact

Diagnostic Information

Pattern Observed

1. Claude maintains full cognitive ability
2. Correctly formulates commands
3. Provides appropriate feedback messages
4. Execution layer appears disconnected
5. No error messages returned from failed operations

Example Command Sequence

# Claude attempts organization
cd /path/to/directory/
mv old_file.md archive/
echo "✅ File archived"
ls -la
# Claude sees original state, but reports success

Severity

HIGH - Core functionality broken, significantly impacts productivity

Potential Causes

1. Session continuation issue after context limit
2. Sandbox/safety limitation triggered
3. File system permissions (though read works)
4. Execution layer timeout or disconnect
5. State management issue in continued session

Workaround

User must manually execute the commands that Claude provides, as the reasoning and
command formulation remain correct.

Additional Notes

• This appears to be an execution layer issue, not a reasoning issue
• Claude still correctly reads files and analyzes content
• Issue is reproducible across different file operations
• No error messages are returned, suggesting commands are not reaching execution

Suggested Labels

• bug
• high-priority
• file-operations
• session-continuation