CSOM has no way to create a file in a library with required metadata without filling ii tin as the UI does.

[marcus905]

Target SharePoint environment

SharePoint Online

What SharePoint development model, framework, SDK or API is this about?

SharePoint CSOM

Developer environment

Windows

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

Issue is there in CSOM 16.1.27011.12008, but the same applies to current Power Automate actions.

Describe the bug / error

There is no way to create a file on a library (even leaving it checked out) without filling in the properties at the same time in a way that matches the UI (both modern/classic). The upload without properties will always fail with a "List data validation failed." error.

Steps to reproduce

execute something like this on a library with required metadata and no defaults:

using (MemoryStream contentStream = new())
{
    // Add an empty file.

    uploadFolder = destinationClientContext.Web.GetFolderByServerRelativeUrl(Path.Combine(site.AbsoluteUri,uploadFolderServerRelativeURL));
    destinationClientContext.Load(uploadFolder, f => f.ServerRelativeUrl);
    await destinationClientContext.ExecuteQueryAsync();

    FileCreationInformation emptyFci = new()
    {
        ContentStream = contentStream,
        Url = destinationFileName,
        Overwrite = true
    };

    uploadFile = uploadFolder.Files.Add(emptyFci);

    // push content in chunks... doesn't matter.

    await destinationClientContext.ExecuteQueryAsync();
}

Expected behavior

The file should be uploaded but be checked out -- OR -- there should be a switch in the FileCreationInformation like CheckRequiredFields (as SaveBinary). The same should apply to the Power Automate actions.

[marcus905]

On top of the above, it appears there is no way to create a file at all in this situation as the file creation will trigger the validation failure even when the metadata is added at any point after the Add() call on the folder as that call will fail before metadata has a chance to be added to avoid the issue.

[marcus905]

And ultimately, the Modern UI will show the same "List data validation failed." in this case:

the call fails at the same point in the flow as CSOM:

  {
           "request": {
          "method": "POST",
          "url": "https://xxx.sharepoint.com/sites/yyy/.../_api/web/GetFolderByServerRelativePath(DecodedUrl=@a1)/Files/AddStubUsingPath(DecodedUrl=@a2)/Upload(uploadId=@a3)?@a1=%27%2Fsites%2F...%27&@a2=%27100mb%2Epdf%27&@a3=guid%27dd68e579-2ac8-4b5c-bc84-07a34dd116b2%27&$Select=ServerRelativeUrl,UniqueId,Name,VroomItemID,VroomDriveID,ServerRedirectedUrl,WebId,SiteId,ListId&$Expand=ListItemAllFields/ContentType/Fields",
          "httpVersion": "h3",
          "headers": [
           
            {
              "name": ":scheme",
              "value": "https"
            },
            {
              "name": "accept",
              "value": "application/json;odata=verbose"
            },
            {
              "name": "accept-encoding",
              "value": "gzip, deflate, br, zstd"
            },
            {
              "name": "accept-language",
              "value": "en-US,en;q=0.9,it-IT;q=0.8,it;q=0.7,de;q=0.6,es;q=0.5"
            },
            {
              "name": "application",
              "value": "SPList Web"
            },
            {
              "name": "cache-control",
              "value": "no-cache"
            },
            {
              "name": "collectspperfmetrics",
              "value": "SPSQLQueryCount"
            },
            {
              "name": "content-length",
              "value": "104970204"
            },
            {
              "name": "content-type",
              "value": "application/octet-stream"
            },
            {
              "name": "origin",
              "value": "https://luxotticagroup.sharepoint.com"
            },
            {
              "name": "pragma",
              "value": "no-cache"
            },
            {
              "name": "prefer",
              "value": "RetrieveArchiveFileErrorCode"
            },
            {
              "name": "priority",
              "value": "u=1, i"
            },
            {
              "name": "referer",
              "value": "https://xxx.sharepoint.com/sites/yyy/.../Forms/AllItems.aspx"
            },
            {
              "name": "scenario",
              "value": "UploadFile"
            },
            {
              "name": "scenariotype",
              "value": "AUO"
            },
            {
              "name": "sec-ch-ua",
              "value": "\"Google Chrome\";v=\"147\", \"Not.A/Brand\";v=\"8\", \"Chromium\";v=\"147\""
            },
            {
              "name": "sec-ch-ua-mobile",
              "value": "?0"
            },
            {
              "name": "sec-ch-ua-platform",
              "value": "\"Windows\""
            },
            {
              "name": "sec-fetch-dest",
              "value": "empty"
            },
            {
              "name": "sec-fetch-mode",
              "value": "cors"
            },
            {
              "name": "sec-fetch-site",
              "value": "same-origin"
            },
            {
              "name": "user-agent",
              "value": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36"
            },
            {
              "name": "x-requestdigest",
              "value": "0xA3E8C9736511DA29494F0D1583311519A8A592EBACF03DD6D64D064DDFBED6FA383DFA3E42CF4587C57D525FD9B47DD32E9B34FEDD3A2CCA49348F3617DBA258,04 May 2026 22:05:41 -0000"
            }
          ],
          "cookies": [],
          "headersSize": -1,
          "bodySize": 0
        },
        "response": {
          "status": 500,
          "statusText": "",
          "httpVersion": "h3",
          "headers": [
            {
              "name": "alt-svc",
              "value": "h3=\":443\";ma=86400"
            },
            {
              "name": "cache-control",
              "value": "private, max-age=0"
            },
            {
              "name": "content-security-policy",
              "value": "frame-ancestors 'self' teams.microsoft.com *.teams.microsoft.com *.skype.com *.teams.microsoft.us local.teams.office.com teams.cloud.microsoft *.office365.com goals.cloud.microsoft *.powerapps.com *.powerbi.com *.yammer.com engage.cloud.microsoft word.cloud.microsoft excel.cloud.microsoft powerpoint.cloud.microsoft *.officeapps.live.com *.office.com *.microsoft365.com m365.cloud.microsoft *.cloud.microsoft *.stream.azure-test.net *.dynamics.com *.microsoft.com onedrive.live.com *.onedrive.live.com teams.microsoft.com *.teams.microsoft.com securebroker.sharepointonline.com;"
            },
            {
              "name": "content-type",
              "value": "application/json;odata=verbose;charset=utf-8"
            },
            {
              "name": "dataserviceversion",
              "value": "3.0"
            },
            {
              "name": "date",
              "value": "Mon, 04 May 2026 22:06:11 GMT"
            },
            {
              "name": "expires",
              "value": "Sun, 19 Apr 2026 22:06:02 GMT"
            },
            {
              "name": "isocdi",
              "value": "0"
            },
            {
              "name": "last-modified",
              "value": "Mon, 04 May 2026 22:06:02 GMT"
            },
            {
              "name": "microsoftsharepointteamservices",
              "value": "16.0.0.27215"
            },
            {
              "name": "ms-cv",
              "value": "ohBzO7BwARALl/Hq096i9A.0"
            },
            {
              "name": "nel",
              "value": "{\"report_to\":\"network-errors\",\"max_age\":7200,\"success_fraction\":0.001,\"failure_fraction\":1.0}"
            },
            {
              "name": "p3p",
              "value": "CP=\"ALL IND DSP COR ADM CONo CUR CUSo IVAo IVDo PSA PSD TAI TELo OUR SAMo CNT COM INT NAV ONL PHY PRE PUR UNI\""
            },
            {
              "name": "report-to",
              "value": "{\"group\":\"network-errors\",\"max_age\":7200,\"endpoints\":[{\"url\":\"https://spo.nel.measure.office.net/api/report?tenantId=2efb69f2-be2d-41ca-881d-af569ebe098d&destinationEndpoint=Edge-Prod-MIL30r4d&frontEnd=AFD&RemoteIP=79.12.99.0\"}]}"
            },
            {
              "name": "request-id",
              "value": "3b7310a2-70b0-1001-0b97-f1ead3dea2f4"
            },
            {
              "name": "spclientservicerequestduration",
              "value": "9673"
            },
            {
              "name": "splogid",
              "value": "3b7310a2-70b0-1001-0b97-f1ead3dea2f4"
            },
            {
              "name": "sprequestguid",
              "value": "3b7310a2-70b0-1001-0b97-f1ead3dea2f4"
            },
            {
              "name": "strict-transport-security",
              "value": "max-age=31536000"
            },
            {
              "name": "vary",
              "value": "Origin"
            },
            {
              "name": "x-1dscollectorurl",
              "value": "https://eu-mobile.events.data.microsoft.com/OneCollector/1.0/"
            },
            {
              "name": "x-ariacollectorurl",
              "value": "https://eu-mobile.events.data.microsoft.com/Collector/3.0/"
            },
            {
              "name": "x-aspnet-version",
              "value": "4.0.30319"
            },
            {
              "name": "x-cache",
              "value": "CONFIG_NOCACHE"
            },
            {
              "name": "x-content-type-options",
              "value": "nosniff"
            },
            {
              "name": "x-databoundary",
              "value": "EU"
            },
            {
              "name": "x-frame-options",
              "value": "SAMEORIGIN"
            },
            {
              "name": "x-ms-invokeapp",
              "value": "1; RequireReadOnly"
            },
            {
              "name": "x-msedge-ref",
              "value": "Ref A: C5CF6ADC194D4E0F8B61A2725DED4D11 Ref B: MIL30EDGE1505 Ref C: 2026-05-04T22:06:02Z"
            },
            {
              "name": "x-networkstatistics",
              "value": "0,524280,0,52,3186355,525568,525568,17387"
            },
            {
              "name": "x-powered-by",
              "value": "ASP.NET"
            },
            {
              "name": "x-requestdigest",
              "value": "0xAD62431436E10BCF901228DD2019C9CF1CDCA370663408626CB672F31FA955F2F889212D99D691BC33EF71087C525E93D3B2AE97656DB831E5194490BF878EFF,04 May 2026 22:06:12 -0000"
            },
            {
              "name": "x-sharepointhealthscore",
              "value": "3"
            },
            {
              "name": "x-sp-serverstate",
              "value": "ReadOnly=0"
            }
          ],
          "cookies": [],
          "content": {
            "size": 132,
            "mimeType": "application/json"
          },
          "redirectURL": "",
          "headersSize": -1,
          "bodySize": -1,
          "_transferSize": 3204,
          "_error": null,
          "_fetchedViaServiceWorker": false
        },
        "serverIPAddress": "13.107.138.10",
        "startedDateTime": "2026-05-04T22:06:03.249Z",
        "time": 9912.062000017613,
        "timings": {
          "blocked": 3.2910000105686485,
          "dns": -1,
          "ssl": -1,
          "connect": -1,
          "send": 6211.195,
          "wait": 3594.313999988314,
          "receive": 103.26200001873076,
          "_blocked_queueing": 2.0730000105686486,
          "_workerStart": -1.647,
          "_workerReady": -1.056,
          "_workerFetchStart": -1,
          "_workerRespondWithSettled": -1
        },
        "_connectionId": "444534"
      }

the response content (missing from the HAR excerpt) is:

{
    "error": {
        "code": "-2130575162, Microsoft.SharePoint.SPException",
        "message": {
            "lang": "en-US",
            "value": "List data validation failed."
        }
    }
}

[Ashlesha-MSFT]

Hello @marcus905,
Thank you for bringing this issue to our attention. We will look into it and get back to you shortly.

[Ashlesha-MSFT]

@marcus905,

After reviewing this, the List data validation failed error here is expected server behavior rather than a CSOM bug. SharePoint enforces required field validation server-side at the moment the list item is committed, which happens immediately when Files.Add() is called. There is currently no flag on FileCreationInformation to defer or suppress that validation — unlike the older SaveBinary which had a CheckRequiredFields parameter. Your HAR trace also confirms the Modern UI hits the same 500 when metadata is missing; it avoids the error by collecting metadata in the upload panel and submitting everything atomically.

[marcus905]

The Classic UI allowed the upload to proceed without metadata and left the file checked out until there was metadata put in. The Modern UI does not allow the file to upload at all in drag&drop and I believe it's a regression, uploading instead via the button was not tried.

There should be a way to proceed with this, using CSOM/REST/PA at least, as there is no way to even put metadata in on a file before adding on a library with required fields and no defaults in there, else there's no way to use this validation for these libraries at all.