Error when setting a value to Multivalue Managed metadata field type using SharePoint REST API - sharepoint-2013

Question

I have two managed metadata fields in my list, they both can have multiple values, the first one is 'mm' and the second one has a danish symbol Ø - 'mm_Ø'.
I fetch the fields information using SharePoint REST API endpoint:
GET https://{tenant}.sharepoint.com/{site-path}/_api/Web/Lists(guid'{list-id}')/fields
In the response I see my fields definitions:
The 'mm' field is:
{
"odata.type": "SP.Taxonomy.TaxonomyField",
***
"CanBeDeleted": true,
"ClientSideComponentId": "00000000-0000-0000-0000-000000000000",
"ClientSideComponentProperties": null,
"ClientValidationFormula": null,
"ClientValidationMessage": null,
"CustomFormatter": null,
"DefaultFormula": null,
"DefaultValue": "",
"Description": "",
"Direction": "none",
"EnforceUniqueValues": false,
"EntityPropertyName": "mm",
"Filterable": true,
"FromBaseType": false,
"Group": "Custom Columns",
"Hidden": false,
"Id": "f863fab3-5611-4d81-82f9-299c42e6258c",
"Indexed": false,
"IndexStatus": 0,
"InternalName": "mm",
"JSLink": "SP.UI.Taxonomy.js|SP.UI.Rte.js(d)|SP.Taxonomy.js(d)|ScriptForWebTaggingUI.js(d)",
"PinnedToFiltersPane": false,
"ReadOnlyField": false,
"Required": false,
"SchemaXml": "***",
"Scope": ***,
"Sealed": false,
"ShowInFiltersPane": 0,
"Sortable": false,
"StaticName": "mm",
"Title": "mm",
"FieldTypeKind": 0,
"TypeAsString": "TaxonomyFieldTypeMulti",
"TypeDisplayName": "Managed Metadata",
"TypeShortDescription": "Managed Metadata",
"ValidationFormula": null,
"ValidationMessage": null,
"AllowMultipleValues": true,
"DependentLookupInternalNames": [],
"IsDependentLookup": false,
"IsRelationship": true,
"LookupField": "Term$Resources:core,Language;",
"LookupList": "{6eaf0d27-f293-4017-bac5-b3ef9b3fe079}",
"LookupWebId": "e0087d65-0dcb-41a5-bb7c-c4b2f94fed59",
"PrimaryFieldId": null,
"RelationshipDeleteBehavior": 0,
"UnlimitedLengthInDocumentLibrary": false,
"AnchorId": "00000000-0000-0000-0000-000000000000",
"CreateValuesInEditForm": false,
"IsAnchorValid": true,
"IsKeyword": false,
"IsPathRendered": false,
"IsTermSetValid": true,
"Open": true,
"SspId": "a1796552-9a87-4f1d-95d5-b4a3fc8f143d",
"TargetTemplate": null,
"TermSetId": "8ed8c9ea-7052-4c1d-a4d7-b9c10bffea6f",
"TextField": "93148f4a-853f-4851-a600-3f76b38d030a",
"UserCreated": false
}
And the 'mm_Ø' field:
{
"odata.type": "SP.Taxonomy.TaxonomyField",
***
"AutoIndexed": false,
"CanBeDeleted": true,
"ClientSideComponentId": "00000000-0000-0000-0000-000000000000",
"ClientSideComponentProperties": null,
"ClientValidationFormula": null,
"ClientValidationMessage": null,
"CustomFormatter": null,
"DefaultFormula": null,
"DefaultValue": "",
"Description": "",
"Direction": "none",
"EnforceUniqueValues": false,
"EntityPropertyName": "mm__x00d8_",
"Filterable": true,
"FromBaseType": false,
"Group": "Custom Columns",
"Hidden": false,
"Id": "8b6cb6c7-5bdf-4e87-95e0-8ad6db1bc60e",
"Indexed": false,
"IndexStatus": 0,
"InternalName": "mm__x00d8_",
"JSLink": "SP.UI.Taxonomy.js|SP.UI.Rte.js(d)|SP.Taxonomy.js(d)|ScriptForWebTaggingUI.js(d)",
"PinnedToFiltersPane": false,
"ReadOnlyField": false,
"Required": false,
"SchemaXml": "***",
"Scope": ***,
"Sealed": false,
"ShowInFiltersPane": 0,
"Sortable": false,
"StaticName": "mm__x00d8_",
"Title": "mm_Ø",
"FieldTypeKind": 0,
"TypeAsString": "TaxonomyFieldTypeMulti",
"TypeDisplayName": "Managed Metadata",
"TypeShortDescription": "Managed Metadata",
"ValidationFormula": null,
"ValidationMessage": null,
"AllowMultipleValues": true,
"DependentLookupInternalNames": [],
"IsDependentLookup": false,
"IsRelationship": true,
"LookupField": "Term$Resources:core,Language;",
"LookupList": "{6eaf0d27-f293-4017-bac5-b3ef9b3fe079}",
"LookupWebId": "e0087d65-0dcb-41a5-bb7c-c4b2f94fed59",
"PrimaryFieldId": null,
"RelationshipDeleteBehavior": 0,
"UnlimitedLengthInDocumentLibrary": false,
"AnchorId": "00000000-0000-0000-0000-000000000000",
"CreateValuesInEditForm": false,
"IsAnchorValid": true,
"IsKeyword": false,
"IsPathRendered": false,
"IsTermSetValid": true,
"Open": true,
"SspId": "a1796552-9a87-4f1d-95d5-b4a3fc8f143d",
"TargetTemplate": null,
"TermSetId": "8ed8c9ea-7052-4c1d-a4d7-b9c10bffea6f",
"TextField": "b658e553-725e-4e24-9a6a-c911b50d68a4",
"UserCreated": false
}
Now, I want to create an item in that list using REST endpoint:
POST https://{tenant}.sharepoint.com/{site-path}/_api/Web/Lists(guid'{list-id}')/items
First I try to create an item only filling the mm field
Body:
{
"Title": "Item1",
"f863fab356114d8182f9299c42e6258c": "taxonomy|24a5a5fa-7a1d-48d6-8a2d-7937429dfd71;taxonomy2|23901385-e142-458c-85f2-4b5ca5dbd812"
}
And it works. Now I want to do the same but filling the 'mm_Ø' field.
Body:
{
"Title": "ee",
"l910ce92c882443cb3134a7aeed731f7": "taxonomy|24a5a5fa-7a1d-48d6-8a2d-7937429dfd71;taxonomy2|23901385-e142-458c-85f2-4b5ca5dbd812"
}
The response I get:
{
"odata.error": {
"code": "-2130575340, Microsoft.SharePoint.SPException",
"message": {
"lang": "en-US",
"value": "One or more field types are not installed properly. Go to the list settings page to delete these fields."
}
}
}
Does it mean that having symbols other than English in the Managed Metadata causes SharePoint REST API to fail?

Answer 1

From what I can tell, if the meta data field title is too long (each non-standard English letter is 8 letters) then we are getting this error.
Couldn't find a solution except renaming to something shorter/no special characters.
Another solution is to use this new API:
https://[tenant].sharepoint.com/sites/test/_api/web/GetList(#a1)/AddValidateUpdateItemUsingPath()?#a1=%27%2Fsites%2Ftest%2FLists%2FMyList%27
=== update ===
Found a solution, might help you.
In our case, the hidden note field's title was created with wrong value.
it suppose to be "[meta data title]_0" but the special characters were cut off.
If I manually updated the hidden note field's title to "[meta data title]_0" the update works as expected.
It leads me to believe the API in the back end is relying on the field title instead of internal name/TextField property to map the value from the note field back to the meta data field.