Claude Code v2.1.156

Released May 29, 2026 (3 months ago).

"References this build" means the issue body mentions running 2.1.156 (from the bug-report template). It reflects report volume, not a proven defect count — an issue may mention a version without being caused by it. First-party data from the anthropics/claude-code tracker.

Top issues reported on v2.1.156

Ranked by community engagement (reactions and comments).

• [BUG] Inline KaTeX math (`$...$`) no longer renders in chat output — only block `$$...$$` works (regression)
  Open 💬 28 👍 75 #65632
• [BUG] Error: Error during compaction: API Error: Usage credits required for 1M context · turn on usage credits at claude.ai/settings/usage, or use --model to switch to standard context
  Open 💬 41 👍 26 #63896
• Opus 4.8 not selectable in CLI `/model` despite being available on account
  Open 💬 27 👍 20 #63456
• [BUG] Opus 4.8 repeatedly emits malformed tool_use blocks, entire response discarded (4.7 works fine)
  Open 💬 13 👍 18 #63604
• [Bug] Parallel tool calls trigger persistent "Cancelled" errors
  Resolved 💬 9 👍 19 #63576
• [Bug] Agent spams no-op echo probe commands to flush shell output
  Open 💬 5 👍 17 #63887
• [BUG] AUP/cyber-safeguard false positives on legitimate own-software hardening; one hit contaminates entire session
  Open 💬 15 👍 12 #63751
• [BUG] API 400 "messages[1].role must be either 'user' or 'assistant', but got 'system'" (v2.1.156)
  Resolved 💬 23 👍 8 #63469
• [BUG] Stale "Pull request status couldn't be checked" on archived sessions whose repo/worktree was deleted
  Resolved 💬 0 👍 15 #63550
• Effort/model selection ("ultracode") reverts to "extra" when switching chats
  Resolved 💬 12 👍 9 #66266
• [BUG] /claude-api bundled skill saturates context unconditionally — ~77% spike from neutral question
  Resolved 💬 8 👍 9 #63566
• [BUG] /compact fails with cyber safeguards false positive during legitimate defensive security session
  Resolved 💬 9 👍 8 #63499
• [Bug] "workflow" keyword conflicts with tool trigger syntax
  Resolved 💬 3 👍 9 #63425
• Opus claude-opus-4-8 emits unparseable tool calls at ~1.5% rate; opus-4-7 and sonnet-4-6 have 0% failure rate
  Open 💬 8 👍 7 #64774
• [Bug] Claude 4.8 Opus hallucinating tool outputs without execution
  Open 💬 7 👍 7 #64076
• [Bug] Anthropic API Error: Usage credits required for 1M context with 1M context disabled
  Resolved 💬 13 👍 5 #63761
• [BUG] Claude Code for VS Code API Error: 400 messages[1].role must be either 'user' or 'assistant', but got 'system'
  Resolved 💬 25 👍 1 #63473
• [BUG] Opus 4.8 in Claude Code declares work "verified" / "done" without running the canonical build — false-green regression vs. Opus 4.7
  Resolved 💬 9 👍 6 #63861
• [Bug] Claude Opus 4.8: Tool call parsing fails when extended thinking is triggered
  Resolved 💬 3 👍 8 #63481
• Doing useless tool call wasting token
  Resolved 💬 5 👍 7 #64009
• [Bug] /compact fails with "Usage credits required for 1M context" even after /model set to Sonnet 4.6
  Resolved 💬 10 👍 5 #63634
• VS Code extension ignores sandbox settings.json / /sandbox unavailable (approval-fatigue fix unreachable in IDE)
  Resolved 💬 5 👍 6 #64061
• [BUG] CLAUDE_CODE_DISABLE_1M_CONTEXT ignored in 2.1.156
  Resolved 💬 7 👍 5 #63479
• Bash/Read tool results intermittently return empty (then flush late, redundantly) on Linux — NOT length/concurrency-correlated; same symptom as stale-closed #36038
  Resolved 💬 12 👍 2 #63797
• [BUG] Bash and Read tool outputs arriving one turn late
  Resolved 💬 3 👍 4 #63766
• Code-tab Customize -> Skills is missing skills that are present in ~/.claude/skills (non-deterministic; / menu and engine load them all)
  Open 💬 2 👍 4 #64466
• [BUG] Desktop local-agent (Claude Code): 900s session idle timeout tears down the computer-use connector and never re-registers it on resume
  Resolved 💬 1 👍 4 #64433
• [Bug] Opus 4.7 & 4.8 — silent stuck-turn: stop_reason=tool_use with no tool_use block (Sonnet 4.6 unaffected)
  Resolved 💬 4 👍 3 #63583
• [BUG] ClaudeCodeManager-VM Checksum Mismatch on macOS Apple Silicon — v1.9659.2
  Resolved 💬 10 👍 1 #63531
• Model Opus 4.8 False positive safety block: innocent Gmail MCP question blocked as "cyber threat"
  Resolved 💬 3 👍 3 #63709

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