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 jobs that page through a large universe, refresh the token before it expires, and retry any request that returns 401 after refreshing.

See Authentication.

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 response says Invalid source input for and names a parameter, for example domicileCode. The parameter doesn't belong to the investment type of the request.

• exchangeCode is the primary filter for equities. Don't use it with source=managedInvestments.
• countryAvailableForSaleCode and domicileCode are primary filters for managed investments. Set source=managedInvestments when you use them. The default source is equities.
• Secondary filters belong to one investment type too. See Get Your Universe.

The response says The Unknown universe Parameter.

• Check the spelling of the universe value. It must be the name of a custom universe that was set up for your account.
• Check that you are using the right source. A custom universe is for either equities or managed investments.
• If you don't know the names of your custom universes, contact your Morningstar account manager.

See Get Your Universe.

A filter can be rejected when its value isn't one that the API accepts.

• Use the codes in Filter Values for securityType, shareClassInformationInvestmentType, investmentType and fundLegalStructureName.
• Use an exchange code from your entitlements for exchangeCode, and 3-character ISO 3166-1 country codes for countryAvailableForSaleCode and domicileCode.
• Check that the value is in your entitlements. See Get Your Universe.

• A primary filter is required, and a request can use only one. Don't send countryAvailableForSaleCode and domicileCode together.
• Secondary filters can't be used without a primary filter.
• Secondary filters narrow the primary filter. Don't use one in place of it.

See Get Your Universe.

pageSize must be a whole number from 1 to 50. The default is 50, so you can leave it out.

• Pass the token exactly as it was returned, with no changes.
• Use either paginationTokenNext or paginationTokenPrevious in a request, not both.
• Keep all the other parameters the same as in the request that returned the token.

See Work with Results.

The request succeeded but investments is empty.

• If you sent no primary filter, the response lists your entitlements instead of investments. Add a primary filter. See Work with Results.
• Check that the filter value is in your entitlements. A value that you aren't entitled to returns nothing.
• Check that secondary filters aren't too narrow. Remove them one at a time to find out which one excludes everything.
• Check source. A managed investments filter returns nothing for equities.

• Your universe is limited to your entitlements, so it can be smaller than the whole of the Morningstar universe.
• Secondary filters narrow the results.
• A custom universe is a subset of your entitled universe.
• Check that you retrieved every page. Keep requesting pages until a response has no paginationTokenNext.

This happens when the filters change between requests.

• Keep every parameter except the token the same across the requests for a universe.
• Don't change pageSize or source part of the way through.
• Start again from the first page if you have changed a filter.

See Work with Results.

For managed investments, the identifiers object can contain a different identifier from the performance ID. The performance ID is also in the basicReference data group, as basicReference.performanceId.

See Work with Results.