claude-code - 💡(How to fix) Fix [Bug] Ultraplan: Session creation failed during initialization [1 participants]

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/jmk/.local/share/claude/versions/2.1.112 (expected in multi-process scenarios)\n at Od_ (/$bunfs/root/src/entrypoints/cli.js:2748:2177)\n at Ke6 (/$bunfs/root/src/entrypoints/cli.js:2748:1257)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-04-17T02:15:20.430Z"},{"error":"AxiosError: Request failed with status code 503\n at XU (/$bunfs/root/src/entrypoints/cli.js:110:1194)\n at <anonymous> (/$bunfs/root/src/entrypoints/cli.js:115:12736)\n at emit (node:events:92:22)\n at endReadableNT (internal:streams/readable:865:50)\n at processTicksAndRejections (native:7:39)\n at request (/$bunfs/root/src/entrypoints/cli.js:117:2467)\n at async vg (/$bunfs/root/src/entrypoints/cli.js:2798:7244)\n at async c05 (/$bunfs/root/src/entrypoints/cli.js:6373:102)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-04-17T02:15:34.055Z"},{"error":"AxiosError: Request failed with status code 503\n at XU (/$bunfs/root/src/entrypoints/cli.js:110:1194)\n at <anonymous> (/$bunfs/root/src/entrypoints/cli.js:115:12736)\n at emit (node:events:92:22)\n at endReadableNT (internal:streams/readable:865:50)\n at processTicksAndRejections (native:7:39)\n at request (/$bunfs/root/src/entrypoints/cli.js:117:2467)\n at async vg (/$bunfs/root/src/entrypoints/cli.js:2798:7244)\n at async c05 (/$bunfs/root/src/entrypoints/cli.js:6373:102)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-04-17T02:16:17.109Z"}]

TL;DR

Check for concurrent access issues and server availability to resolve the ultraplan session creation failure.

Guidance

• Investigate the "Lock acquisition failed" error, which may indicate concurrent access to the /Users/jmk/.local/share/claude/versions/2.1.112 directory, potentially caused by multiple processes trying to access it simultaneously.
• Look into the "Request failed with status code 503" errors, which suggest that the server is currently unavailable, possibly due to maintenance or overload.
• Verify that the server is operational and can handle incoming requests.
• Consider implementing retry mechanisms or exponential backoff strategies to handle temporary server unavailability.

Example

No code snippet is provided as it's not clearly supported by the issue.

Notes

The provided errors imply that there might be issues with both local resource locking and remote server availability. Resolving these issues may require adjustments to the application's concurrency handling and server request management.

Recommendation

Apply workaround: Implement retry mechanisms and exponential backoff to handle temporary server unavailability, as the root cause seems to be related to server availability and concurrent access.