can't load dotnet 10 sdk

Question

can't load dotnet 10 sdk

Shao, Seth 0

I get

Failed to load [C:\Program Files\dotnet\host\fxr\10.0.9\hostfxr.dll], HRESULT: 0x800700C1

Ensure the library matches the current process architecture: x64

The library hostfxr.dll was found, but loading it from C:\Program Files\dotnet\host\fxr\10.0.9\hostfxr.dll failed

when I type dotnet --list-sdks

aslo I can neither uninstall dotnet 10 sdk from Apps nor from Visual Studio Installer

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2 answers

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Answer 1

Damien Pham (WICLOUD CORPORATION) 1,755 Microsoft External Staff Moderator

Hello @Shao, Seth ,

Because where.exe dotnet only shows C:\Program Files\dotnet\dotnet.exe, the likely cause is that the system-wide .NET 10 install is damaged or the required native dependency is missing.

I suggest trying this in order:

Run the same .NET 10 installer again and choose Repair, or run it with the documented /repair option. Microsoft documents that the Windows installer supports /repair and /uninstall for an existing SDK install: Install .NET on Windows.
If uninstall from Apps/Visual Studio still does not work, use the Microsoft .NET Uninstall Tool to see whether that SDK can be removed: dotnet-core-uninstall list and uninstall tool overview. If it appears in the list, you can remove it with dotnet-core-uninstall remove.
Reinstall the x64 .NET 10 SDK from the official Windows installer or WinGet package Microsoft.DotNet.SDK.10, as described in Install .NET on Windows.
If the machine is older Windows or missing prerequisites, install the Microsoft Visual C++ Redistributable, because the .NET Windows troubleshooting guidance calls that out for hostfxr.dll-related failures: Troubleshooting on Windows.

If it still fails after repair or reinstall, please share:

your Windows version
whether this is an Arm64 machine
the result of dotnet --info
whether the .NET 10 installer Repair completed successfully

I hope this helps. If you found my response helpful or informative, I would greatly appreciate it if you could follow this guidance or provide feedback.

Thank you.

Shao, Seth 0 Reputation points

2026-06-23T07:19:28.1566667+00:00

I download a new installer from https://dotnet.microsoft.com/en-us/download/dotnet/thank-you/sdk-10.0.301-windows-x64-installer when I tried to install it, it shows like this
Shao, Seth 0 Reputation points

2026-06-23T07:26:11.0266667+00:00

Edition Windows 11 Enterprise

Version 24H2

Installed on ‎2025-‎08-‎12

OS build 26100.8390

Experience Windows Feature Experience Pack 1000.26100.297.0
Damien Pham (WICLOUD CORPORATION) 1,755 Reputation points Microsoft External Staff Moderator

2026-06-23T10:57:53.2366667+00:00
Hello @Shao, Seth ,

Thank you for the screenshots. Windows 11 24H2 is a supported OS for .NET 10, so this no longer looks like an OS support issue.

The new error is the important part: 0x8007064c means Windows Installer can't find the original installation source for the .NET Host FX Resolver package. Microsoft’s Windows guidance explains that when installer cache/source files are missing, repair, update, or uninstall can fail until the owning product restores that source: Missing Windows Installer cache requires a computer rebuild.

Because your screenshot points to C:\ProgramData\Microsoft\VisualStudio\Packages\..., the next step depends on whether this machine has Visual Studio installed:

If Visual Studio is installed, first try the documented Visual Studio repair path: Repair Visual Studio. If repair or uninstall still fails, Microsoft documents InstallCleanup.exe as a last resort cleanup tool: Remove all by using InstallCleanup.exe.

After that cleanup succeeds, reinstall the .NET 10 x64 SDK from the official installer: Install .NET on Windows.

If Visual Studio is not installed on this machine, please say so, because that would change the next step. Also, please let me know whether you are signed in with a local administrator account or otherwise have permission to install/repair software on this machine, because both the Visual Studio repair path and system-wide .NET installation require administrative privileges.
Shao, Seth 0 Reputation points

2026-06-23T14:50:23.0933333+00:00

I've tried dotnet-core-uninstall, it froze here for hours

Then I repaired the VS2026 from Visual Studio Installer, succeeded but still can't run any dotnet cli, same error message

Then I uninstalled VS2026 from Visual Studio Installer, the dotnet 10 sdk was still there. I also ran the InstallCleanup.exe but I have VS2019 and VS2022 installed. I added parameter '-i 2026' but nothing happened.

Then I installed VS2026 again, still same error message.

Our company has several solutions with different runtimes and sdks. One of the solutions can be built by 2022 but not 2026
Shao, Seth 0 Reputation points

2026-06-24T01:48:13.6233333+00:00

I downloaded SDK 10.0.109 then I was able to uninstall 10.0.301 successfully. I think everything is okay now. Thanks for your help.
Damien Pham (WICLOUD CORPORATION) 1,755 Reputation points Microsoft External Staff Moderator

2026-06-24T07:41:47.8433333+00:00

Hello @Shao, Seth ,

Thank you for the update, and I'm glad to hear the issue is now resolved.

The steps outlined in the earlier guidance appear to have helped restore the .NET installation state. In particular, installing .NET SDK 10.0.109 and then removing 10.0.301 successfully aligns with the repair/reinstallation approach suggested above. Given the original error referencing a missing installer source, refreshing the installation through a newer SDK might allow Windows Installer to complete the cleanup of the affected .NET 10.0.301 components.

Thank you for confirming the outcome and sharing the steps that worked in your environment. This information may be helpful to others who encounter a similar installation or uninstall issue in the future.

Answer 2

Shao, Seth 0

only C:\Program Files\dotnet\dotnet.exe listed when running where.exe dotnet

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