icsharpcode/ILSpy · error · ReflectionNameParseException

Expected '}'

Error message

Expected '}'

What it means

ReflectionNameParseException thrown by ReadTypeParameterCountFromIdString when a bound type-argument list opened with '{' is never closed with '}' before the end of the string. The arity counter scans for the matching brace and throws at the position just past the end if it runs off the string.

Solutions

1. Close every '{' with a matching '}' in bound type-argument syntax.
2. Prefer the unbound arity form (e.g. "T:Foo`2") when you only need the type definition lookup.
3. Validate brace balance before passing the ID string to FindEntity.

Example fix

// before
var e = IdStringProvider.FindEntity("T:Foo{System.Int32", context);

// after
var e = IdStringProvider.FindEntity("T:Foo{System.Int32}", context);

static bool BracesBalanced(string s)
{
    int depth = 0;
    foreach (char c in s)
    {
        if (c == '{') depth++;
        else if (c == '}') depth--;
        if (depth < 0) return false;
    }
    return depth == 0;
}

try { return IdStringProvider.FindEntity(idString, context); }
catch (ReflectionNameParseException ex) { logger.Warn($"Unclosed generic args at {ex.Position}: {ex.Message}"); return null; }

When it happens

Trigger: An ID string using bound generic syntax with an unclosed brace, e.g. "T:Foo{Bar" or "T:Foo{Bar,Baz".

Common situations: Truncating a bound-argument ID string; constructing one programmatically and forgetting the closing brace; copying a cref that was itself cut off.

Related errors

• Could not find '.' separating type name from member name
• Expected type name
• Missing type tag
• Cannot compute an ID string for an entity that is not…
• The handle must not be nil.

AI-assisted analysis of icsharpcode/ILSpy@60c08fcb74 (2026-08-13). Data as JSON: /api/errors/5cfc99648f8ee93f. Report an issue: GitHub.

Appendix: source

Thrown at ICSharpCode.Decompiler/Documentation/IdStringProvider.cs:1130

					{
						depth++;
					}
					else if (c == '}')
					{
						if (depth == 0)
						{
							pos++;
							return count;
						}
						depth--;
					}
					else if (c == ',' && depth == 0)
					{
						count++;
					}
					pos++;
				}
				throw new ReflectionNameParseException(pos, "Expected '}'");
			}

			return 0;
		}

		/// <summary>
		/// Attempts to resolve a parsed type name within a single module.
		/// The first part's Name is a dotted name like "A.B.C", and we try all possible
		/// splits between namespace and top-level type name, from right to left.
		/// For each candidate top-level type, we walk the nested types.
		/// Also checks type forwarders.
		/// </summary>
		static EntityHandle ResolveTypeInModule(List<TypeNamePart> parts, MetadataFile module)
		{
			var metadata = module.Metadata;
			string topLevelDottedName = parts[0].Name;
			string[] dotParts = topLevelDottedName.Split('.');

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