Why is my JSON valid but still failing to parse in my application?

Valid JSON fails to parse in applications due to environment-specific issues beyond syntax. Character encoding problems: file saved as UTF-16 but parser expects UTF-8. BOM (Byte Order Mark) at file start confuses some parsers. Invisible Unicode characters like zero-width spaces. File truncated during transmission. Parser receives partial response due to network timeout. Memory limits exceeded with large JSON. Parser library bugs with specific valid constructs. String escape sequences valid in JSON but problematic in parser. Very deep nesting exceeds parser recursion limits. Large numbers exceeding JavaScript Number.MAX_SAFE_INTEGER. Date strings in valid but unexpected format. Parser expects specific JSON structure different from what you provided. Try different JSON parser to isolate issue. Use our JSON Validator at jsonconsole.com/json-editor to verify syntax correctness. Check file encoding with text editor or hex viewer. Log exact string being parsed to see if matches expectation. Test with smaller subset of JSON. Update parser library to latest version. Check parser configuration and limits. Valid JSON syntax does not guarantee successful parsing in all environments—encoding, size, and parser capabilities matter.