[Bug] Anthropic API Error: Cannot modify thinking blocks during compaction

Resolved 💬 3 comments Opened Dec 10, 2025 by victor2ai Closed Dec 14, 2025

Bug Description
got this issue when compacting

/compact

⎿  Error: Error during compaction: Error: API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.3.content.63: 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_011CVyc8us7bDo3tvdoTmevz"}

Environment Info

  • Platform: darwin
  • Terminal: iTerm.app
  • Version: 2.0.61
  • Feedback ID: 1bd42ca5-656d-45ea-8732-d690a1bce6d1

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/victor/.local/share/claude/versions/2.0.61 (expected in multi-process scenarios)\n    at Eh0 (/$bunfs/root/claude:2714:1622)\n    at mCA (/$bunfs/root/claude:2714:1300)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:41:05.394Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:52:43.975Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:53:00.899Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:54:33.805Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:54:54.292Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:55:10.313Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:55:34.013Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:55:53.838Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:56:28.343Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:56:46.749Z"},{"error":"Error\n    at <anonymous> (/$bunfs/root/claude:175:10668)\n    at emit (node:events:92:22)\n    at <anonymous> (/$bunfs/root/claude:174:5634)\n    at request (/$bunfs/root/claude:177:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T17:57:07.280Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.149: `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_011CVwafz1mnouX9TyNKVyNz\"}\n    at generate (/$bunfs/root/claude:109:10367)\n    at makeRequest (/$bunfs/root/claude:1237:5434)\n    at processTicksAndRejections (native:7:39)","timestamp":"2025-12-09T18:24:29.573Z"},{"error":"Error: API Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.149: `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\":\"re

Note: Error logs were truncated.

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