vercel/next.js · error · Error

Detected a three-dot character ('…') at ('${segmentName}').

Error message

Detected a three-dot character ('…') at ('${segmentName}'). Did you mean ('...')?

What it means

_insert detects the single Unicode ellipsis character '…' inside a bracketed dynamic segment name. It is almost always a typo of the three ASCII dots '...' used for catch-all routes; left uncorrected the segment would be treated as an ordinary named slug and silently mis-route.

Source

Thrown at packages/next/src/shared/lib/router/utils/sorted-routes.ts:98

    }

    // The next segment in the urlPaths list
    let nextSegment = urlPaths[0]

    // Check if the segment matches `[something]`
    if (nextSegment.startsWith('[') && nextSegment.endsWith(']')) {
      // Strip `[` and `]`, leaving only `something`
      let segmentName = nextSegment.slice(1, -1)

      let isOptional = false
      if (segmentName.startsWith('[') && segmentName.endsWith(']')) {
        // Strip optional `[` and `]`, leaving only `something`
        segmentName = segmentName.slice(1, -1)
        isOptional = true
      }

      if (segmentName.startsWith('…')) {
        throw new Error(
          `Detected a three-dot character ('…') at ('${segmentName}'). Did you mean ('...')?`
        )
      }

      if (segmentName.startsWith('...')) {
        // Strip `...`, leaving only `something`
        segmentName = segmentName.substring(3)
        isCatchAll = true
      }

      if (segmentName.startsWith('[') || segmentName.endsWith(']')) {
        throw new Error(
          `Segment names may not start or end with extra brackets ('${segmentName}').`
        )
      }

      if (segmentName.startsWith('.')) {
        throw new Error(

View on GitHub (pinned to 0eb3775416)

Solutions

1. Replace the three-dot character … with three periods ... in the segment name.

When it happens

Trigger: A route segment uses the Unicode three-dot ellipsis character.

Common situations: Typing '[…slug]' with the … character instead of three periods in a folder name.

AI-assisted analysis of vercel/next.js@0eb3775416 (2026-08-19). Data as JSON: /api/errors/ea457f7d77c9c820. Report an issue: GitHub.