[Bug] Anthropic API Error: Cannot Modify Thinking Blocks in Assistant Messages

Bug Description
Error: Error during compaction: Error: API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.3.content.9: thinking or redacted_thinking blocks in the latest assistant message cannot be modified. These blocks must remain as they
were in the original response."},"request_id":"req_011CXY2YYH9AoAJ4Y5mn3mJz"}

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.19
• Feedback ID: 3cc2a98c-1776-4de6-a236-caa3af9d4b85

Errors

[{"error":"Error: ENOENT: no such file or directory, scandir '/Library/Application Support/ClaudeCode/.claude/skills'\n    at Module.readdirSync (node:fs:1562:26)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:1766\n    at yO (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:35112)\n    at Object.readdirSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:1736)\n    at _D1 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2284:369)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2284:4279\n    at q (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:6814)\n    at CB2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4920:4362)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4920:6961\n    at q (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:6814)","timestamp":"2026-01-24T19:42:32.266Z"},{"error":"Error: ENOENT: no such file or directory, scandir '/Users/wolf/.claude/skills'\n    at Module.readdirSync (node:fs:1562:26)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:1766\n    at yO (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:35112)\n    at Object.readdirSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:1736)\n    at _D1 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2284:369)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2284:4322\n    at q (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:6814)\n    at CB2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4920:4362)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4920:6961\n    at q (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:6814)","timestamp":"2026-01-24T19:42:32.266Z"},{"error":"Error: EISDIR: illegal operation on a directory, read\n    at Module.readFileSync (node:fs:433:20)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:464\n    at yO (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:35112)\n    at Object.readFileSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:433)\n    at A9K (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:5295:27513)\n    at Object.call (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3965:942)\n    at A$2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3029:20047)","timestamp":"2026-01-24T19:43:16.340Z"},{"error":"MaxFileReadTokenExceededError: File content (29493 tokens) exceeds maximum allowed tokens (25000). Please use offset and limit parameters to read specific portions of the file, or use the GrepTool to search for specific content.\n    at e3K (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3956:3100)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Object.call (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3965:996)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4006:1538","timestamp":"2026-01-24T19:43:46.073Z"},{"error":"Error: ENOENT: no such file or directory, scandir '/Library/Application Support/ClaudeCode/.claude/skills'\n    at Module.readdirSync (node:fs:1562:26)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:1766\n    at yO (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:35112)\n    at Object.readdirSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:1736)\n    at _D1 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2284:369)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:2284:4279\n    at q (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:6814)\n    at CB2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4920:4362)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4920:6961\n   …

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