appsmithorg/appsmith · error · AppsmithPluginException

PE-JSN-4000

PE-JSN-4000

Error message

Plugin failed to parse JSON "{0}"

What it means

PLUGIN_JSON_PARSE_ERROR (PE-JSN-4000). The rowObjects string could not be read as a JSON tree (JsonProcessingException from ObjectMapper.readTree). The plugin expected a JSON list of row objects.

Source

Thrown at app/server/appsmith-plugins/googleSheetsPlugin/src/main/java/com/external/config/RowsBulkUpdateMethod.java:87

                        e.getMessage());
            }
        } else {
            throw new AppsmithPluginException(
                    AppsmithPluginError.PLUGIN_EXECUTE_ARGUMENT_ERROR, ErrorMessages.INVALID_TABLE_HEADER_INDEX);
        }
        JsonNode bodyNode;
        try {
            bodyNode = this.objectMapper.readTree(methodConfig.getRowObjects());
        } catch (IllegalArgumentException e) {
            if (!StringUtils.hasLength(methodConfig.getRowObjects())) {
                throw new AppsmithPluginException(
                        AppsmithPluginError.PLUGIN_EXECUTE_ARGUMENT_ERROR,
                        ErrorMessages.EMPTY_UPDATE_ROW_OBJECTS_MESSAGE,
                        e.getMessage());
            }
            throw new AppsmithPluginException(AppsmithPluginError.PLUGIN_EXECUTE_ARGUMENT_ERROR, e.getMessage());
        } catch (JsonProcessingException e) {
            throw new AppsmithPluginException(
                    AppsmithPluginError.PLUGIN_JSON_PARSE_ERROR,
                    methodConfig.getRowObjects(),
                    ErrorMessages.EXPECTED_LIST_OF_ROW_OBJECTS_ERROR_MSG + " Error: " + e.getMessage());
        }

        if (!bodyNode.isArray()) {
            throw new AppsmithPluginException(
                    AppsmithPluginError.PLUGIN_EXECUTE_ARGUMENT_ERROR, ErrorMessages.REQUEST_BODY_NOT_ARRAY);
        }
        return true;
    }

    @Override
    public Mono<Object> executePrerequisites(MethodConfig methodConfig, OAuth2 oauth2) {
        WebClient client =
                WebClientUtils.builder().exchangeStrategies(EXCHANGE_STRATEGIES).build();
        final RowsGetMethod rowsGetMethod = new RowsGetMethod(this.objectMapper);

View on GitHub (pinned to 8cd9021c24)

Solutions

1. Validate the rowObjects string with a JSON linter before saving the query.
2. Prefer building the payload with JSON.stringify(...) in JS rather than hand-writing it.
3. Read the ' Error: ...' suffix in the message - it carries the exact Jackson parse error location.

Example fix

// before
{
  "rowObjects": "[{rowIndex: 2, name: 'X'},]"
}
// after
{
  "rowObjects": "{{ JSON.stringify(Table1.selectedRows.map(r => ({rowIndex: r.__index, name: r.name}))) }}"
}

ObjectMapper om = new ObjectMapper();
boolean valid;
try { om.readTree(methodConfig.getRowObjects()); valid = true; }
catch (Exception e) { valid = false; }

try {
    method.validateExecutionMethodRequest(config);
} catch (AppsmithPluginException e) {
    if ("PE-JSN-4000".equals(e.getAppsmithError().getCode())) {
        // re-prompt user for valid JSON
    }
}

When it happens

Trigger: rowObjects contains malformed JSON - a trailing comma, unquoted keys, single quotes, a stray bracket, or a partial paste that is not complete JSON.

Common situations: User types JSON manually and makes a syntax error; a binding concatenates strings instead of producing JSON; copy-paste from a spreadsheet cell that strips quotes.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• PE-GSH-5000
• PE-ARG-5000
• PE-ARG-5000
• PE-ARG-5000
• PE-ARG-5000

AI-assisted analysis of appsmithorg/appsmith@8cd9021c24 (2026-08-12). Data as JSON: /api/errors/bf6f9d413c7f09dc. Report an issue: GitHub.