apache/answer · error

validate check exception

Error message

validate check exception

What it means

Check runs the go-playground/validator Struct validation on a model and translates field errors into FormErrorField entries. If the returned error is NOT a validator.ValidationErrors (i.e. an unexpected internal validator failure such as a bad tag or wrong input type), it logs and returns the generic 'validate check exception'.

Source

Thrown at internal/base/validator/validator.go:215

				continue
			}
			firstRune := []rune(field.ErrorMsg)[0]
			if !unicode.IsLetter(firstRune) || !unicode.Is(unicode.Latin, firstRune) {
				continue
			}
			upperFirstRune := unicode.ToUpper(firstRune)
			field.ErrorMsg = string(upperFirstRune) + field.ErrorMsg[1:]
			if !strings.HasSuffix(field.ErrorMsg, ".") {
				field.ErrorMsg += "."
			}
		}
	}()
	err = m.Validate.Struct(value)
	if err != nil {
		var valErrors validator.ValidationErrors
		if !errors.As(err, &valErrors) {
			log.Error(err)
			return nil, errors.New("validate check exception")
		}

		for _, fieldError := range valErrors {
			errField := &FormErrorField{
				ErrorField: fieldError.Field(),
				ErrorMsg:   fieldError.Translate(m.Tran),
			}

			// get original tag name from value for set err field key.
			structNamespace := fieldError.StructNamespace()
			_, fieldName, found := strings.Cut(structNamespace, ".")
			if found {
				originalTag := getObjectTagByFieldName(value, fieldName)
				if len(originalTag) > 0 {
					errField.ErrorField = originalTag
				}
			}
			errFields = append(errFields, errField)

View on GitHub (pinned to 3b9f137061)

Solutions

1. Inspect the server log above this error — the underlying validator error is logged via log.Error(err).
2. Fix the struct's validate tags (e.g. register missing custom validators with validator.RegisterValidation).
3. Ensure the value passed to Check is a struct or pointer to struct.
4. Pin/align the go-playground/validator version and the translator setup.

Example fix

// before
Answer `validate:"omitempty,unknown_rule"`
// after
Answer string `validate:"omitempty,min=1,max=500"`

v := validator.New()
v.RegisterTagNameFunc(func(fld reflect.StructField) string { return fld.Tag.Get("json") })
if err := v.Struct(MyRequest{}); err != nil {
  var ve validator.ValidationErrors
  if !errors.As(err, &ve) { log.Fatalf("validator misconfigured: %v", err) }
}

func isStructPtr(v any) bool {
  rv := reflect.ValueOf(v)
  return rv.Kind() == reflect.Ptr && rv.Elem().Kind() == reflect.Struct
}

form, err := validator.Check(req)
if err != nil {
  if err.Error() == "validate check exception" {
    log.Errorf("validator internal failure: %v", err)
    return 500 // not a user input problem
  }
}

When it happens

Trigger: Passing a value whose type validator can't struct-validate (non-struct, nil pointer misfire, map without register), or a struct with an invalid/misconfigured validate tag that makes the validator return a non-ValidationErrors error.

Common situations: Developer adds a custom validator tag without registering it, misuses tags like `validate:"-"` incorrectly, passes a non-struct to Check, or upgrades go-playground/validator causing tag incompatibilities.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• base.request_format_error
• error.password.space_invalid
• decode image config error: %v
• image size too large
• the password does not satisfy the current policy requirement

AI-assisted analysis of apache/answer@3b9f137061 (2026-09-05). Data as JSON: /api/errors/3c038d4b29147a52. Report an issue: GitHub.