stride3d/stride · error · SyntaxErrorException

Block sequence entries are not allowed in this context.

Error message

Block sequence entries are not allowed in this context.

What it means

A '-' block sequence entry indicator was found where a new sequence entry is not permitted. In block context, a '-' entry can only start where a new node may begin; here simpleKeyAllowed is false (e.g. '-' appears after another scalar on the same line).

Solutions

Put each '- item' on its own line at consistent indentation
Remove the '-' if the sequence was meant to be inline (use [a, b] flow style instead)
Ensure the '-' follows a line break or a key ending with ':'

Example fix

// before
key: value - next
// after
key:
  - value
  - next

Defensive patterns

Strategy: validation

Validate before calling

// Block sequence entries must start at line beginning after indentation
var lines = yamlText.Split('\n'); foreach (var l in lines) { var idx = l.IndexOf(" - "); if (idx > 0 && l.Substring(0, idx).Trim().Length > 0 && !l.Substring(0, idx).TrimEnd().EndsWith(":")) throw new FormatException("Inline '-' after scalar: " + l); }

Try / catch

catch (SyntaxErrorException ex) { throw new ConfigFormatException($"'-' not allowed near {ex.Start.Line}:{ex.Start.Column}"); }

Prevention

Put each '- item' on its own line
Use flow style [a, b] for inline lists instead of '-'
Keep indentation consistent for sequence entries

When it happens

Trigger: Writing '- item' on the same line as a previous scalar (e.g. 'key: value - next'), or a '-' appearing after a key without a value separator in a position the scanner disallows.

Common situations: Collapsing list items onto one line in a config file, or converting block style to inline style incorrectly (a '-' inside a flow sequence is invalid).

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/aea230b320d6417b. Report an issue: GitHub.

Appendix: source

Thrown at sources/core/Stride.Core.Yaml/Scanner.cs:942

            // Create the FLOW-ENTRY token and append it to the queue.

            tokens.Enqueue(new FlowEntry(start, mark));
        }

        /// <summary>
        /// Produce the BLOCK-ENTRY token.
        /// </summary>
        private void FetchBlockEntry()
        {
            // Check if the scanner is in the block context.

            if (flowLevel == 0)
            {
                // Check if we are allowed to start a new entry.

                if (!simpleKeyAllowed)
                {
                    throw new SyntaxErrorException(mark, mark, "Block sequence entries are not allowed in this context.");
                }

                // Add the BLOCK-SEQUENCE-START token if needed.
                RollIndent(mark.Column, -1, true, mark);
            }
            else
            {
                // It is an error for the '-' indicator to occur in the flow context,
                // but we let the Parser detect and report about it because the Parser
                // is able to point to the context.
            }

            // Reset any potential simple keys on the current flow level.

            RemoveSimpleKey();

            // Simple keys are allowed after '-'.

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