pnpContext.Web.GetFolder* methods throws the wrong error

[BitRevenant]

Category

• Bug

Describe the bug

In case a folder does not exist, all methods pnpContext.Web.GetFolder* throw the wrong error.

HttpResponseCode: 404
Code: System.IO.FileNotFoundException
Message: File not found.
ClientRequestId: ...
SPClientServiceRequestDuration: 19
X-SharePointHealthScore: 0
X-SP-SERVERSTATE: ReadOnly=0

PnP.Core.SharePointRestServiceException: SharePoint Rest service exception
   at PnP.Core.Services.BatchClient.ExecuteSharePointRestInteractiveAsync(Batch batch)
   at PnP.Core.Services.BatchClient.ExecuteSharePointRestBatchAsync(Batch batch)
   at PnP.Core.Services.BatchClient.ExecuteBatch(Batch batch)
   at PnP.Core.Model.BaseDataModel`1.BaseRetrieveAsync(ApiCall apiOverride, Func`2 fromJsonCasting, Action`1 postMappingJson, Expression`1[] expressions)
   at PnP.Core.Model.SharePoint.Web.GetFolderByIdAsync(Guid folderId, Expression`1[] expressions)
...

Steps to reproduce

Just try pnpContext.Web.GetFolderByIdAsync(folderId) or any method for getting a folder by passing a parameter indicating a non-existent folder.

Expected behavior

Code is: FileNotFoundException and should be DirectoryNotFoundException
Message is: "File not found." and should be "Folder not found."

Environment details (development & target environment)

• SDK version: 1.15.0
• OS: Windows 11 Version 25H2
• SDK used in: ASP.NET Core Web API
• Framework: .NET 10
• Browser(s): Testing APIs with Postman
• Tooling: Visual Studio 2026
• Additional details:

Additional context

Thanks for your contribution! Sharing is caring.

[ejazhussain]

I've submitted PR #1725 to fix this issue.

The fix normalizes the error code from System.IO.FileNotFoundException to System.IO.DirectoryNotFoundException when GetFolderByServerRelativeUrlAsync or GetFolderByIdAsync encounter a non-existent folder.

Root cause: SharePoint REST API returns Windows error code -2147024894 (ERROR_FILE_NOT_FOUND) for both files and folders. The fix adds context-aware normalization in the GetFolder* methods.

[BitRevenant]

In addition to the Exception, did you also fix the message, as I indicated in the bug?

[ejazhussain]

Yes! The message will show as Folder not found

[BitRevenant]

Great, then when I have time I'll report another fairly significant bug. Can you tell me when it will be published in the stable release (not nightly)?

[ejazhussain]

@Marko97IT, we are currently merging the pull request. I will share the details as soon as we have merged it into the stable release.

[Adam-it]

@Marko97IT I've just merged the PR with the fix and this will be part of the next nightly. Sorry for the holdup.
Also, I am not sure of the actual date of the next stable release due to #1703, and from what I am aware, the plan is to make this project part of .NET foundation and obtain a sign certificate from that org, the same as PnP PowerShell, and from what I am aware, we are currently waiting for this to get confirmed. Being part of .NET Foundation will make PnP Core independent from a single person and this product will join a stable and wide org which will increase stability but to make this happen still some time is needed.
Till then, the recommendation is to use nightly builds.

@ejazhussain amazing work. You Rock 🤩