A 401 response from POST /token/oauth means the credentials were rejected.

• Use the Client ID and Client Secret issued to an application in your portal profile. These are separate from the username and password you use to log in to Morningstar for Developers.
• Send the credentials as HTTP Basic authentication, using a Base64-encoded clientId:clientSecret pair.
• Check for extra spaces or line breaks in the values when you copy them.

See Getting Started.

The token is missing, invalid or expired.

• Check that the Authorization header is present and uses the format Bearer {token}.
• Tokens expire after 60 minutes. Request a new token from POST /token/oauth, then retry the request.
• In long-running jobs, refresh the token before it expires, and retry any request that returns 401 after refreshing.

Trial responses are limited to a sample universe, so investments outside it return no data.

• Check metadata.messages in the response to see which identifiers returned no results.
• Try investments that are in the sample universe.
• For full data coverage and production access, contact Morningstar sales.

The request is invalid. The message in the response describes the problem.

• Read the message and errorCode, then find the parameter it names.
• Check the parameters against the API Inputs reference.
• If you can't find the cause, contact support and include the requestId.

The frequency value isn't supported for the request, for example Invalid frequency 'm' for datapoint 'daily-closing-price'.

• Use one of daily, weekly, monthly, quarterly or annually. Values such as m or annual aren't accepted.
• Check that the data point supports the frequency you chose. The message names the data point.

startDate and endDate must be in yyyy-MM-dd format, for example 2024-01-31. Check for missing leading zeros, a different separator or a day and month in the wrong order.

A request can include a maximum of 25 investments. Split larger lists across several requests.

The maximum lookback depends on the frequency and the observation type.

Split a longer range into several requests, or use a lower frequency. This applies to sinceInception as well, which returns data from inception or from the maximum supported lookback.

The category and data point in the path must match an endpoint.

• Check the spelling of both. Data point names are lowercase and hyphenated.
• Check that the data point exists in the category you used. Some data points are in more than one category, and others are in only one.
• See Choose a Data Point for how to find the right endpoint.

sinceInception doesn't work with multivariate data points. Currently the only one is daily-ohlcv. Use startDate and endDate or timePeriod and timePeriodUnit instead, and keep the range within 6 months, which is the multivariate lookback limit.

The request succeeded but one of your investments has no data. Unmatched investments are listed in metadata.messages, and the investments array contains only the ones that returned data.

1. Check metadata.messages.investments for the identifier and its idType.
2. Check the identifier for typos.
3. Check that the idTypes entry matches the identifier. The list lines up with ids by position, so a missing entry shifts the types.
4. Check whether a lookup filter, such as domicile or exchangeCountry, is excluding the investment.
5. Try a different identifier for the same investment. The Morningstar Performance ID is the most precise.

See Work with Results.

An identifier such as a trading symbol can match more than one investment.

• Add lookup filters, such as exchangeCountry, domicile, baseCurrency or exchangeId, to narrow the match.
• Check the metadata of each investment in the response to see the lookup values that were applied.
• Use a Performance ID, which identifies a single investment.

See Specify Investments.

If you combine time range settings, some override others.

• sinceInception overrides timePeriod, timePeriodUnit, startDate and endDate.
• timePeriod and timePeriodUnit override startDate and endDate.

Remove the settings you don't want, so that only one approach is used. See Set the Time Range.

The data for an investment can start later than the startDate you requested.

• The investment may have been launched after startDate.
• If applyEarliestCommonDate is true, every series starts at the latest inception date among the requested investments.
• Set applyTrackRecordExtension to true to extend an investment's history with the performance of a qualified, older investment, if that suits your use.

See Set the Time Range.

By default each time series starts at the earliest date available for its own investment. To make all series start on the same date, set applyEarliestCommonDate to true. To also consider restructure dates when finding that date, set applyRestructureDate to true, which works only together with applyEarliestCommonDate.

• Check frequency. The default is daily, and lower frequencies return fewer observations.
• Check that the range is within the lookback limit for the frequency.
• Check whether the investment has data for the whole range.

By default, data is returned in the investment's base currency (currencyId is BAS). Set currencyId to the currency you want, for example USD. See Request Time Series Data.

A computed data point uses total performance by default. If you pass two performanceType values and the first returns no data, the second is used.

• Check the performanceType in the timeSeries object of the response to see which type was applied.
• Pass only one value if you don't want a fallback.

See Configure Computed Data Points.

When currencyId is EUR and startDate is before 1999, set preCurrency for computed data points so that earlier periods can be converted from the original currency. See Configure Computed Data Points.

Most data points return a date and a single value. daily-ohlcv returns several fields for each date. Use the dataPoint value in each timeSeries object to choose how to parse data. See Work with Results.