A Microsoft open-source framework for building native device applications spanning mobile, tablet, and desktop.
Yes. The error is a toolchain mismatch: the build is using .NET for iOS 26.0.11017, which was validated for Xcode 26.0, while the Mac now has Xcode 27.0 selected.
The supported fixes are:
- Install the Xcode version required by the error
- Install Xcode 26.0 alongside Xcode 27.0.
- Then select the required Xcode on the Mac with:
xcode-select --switch <path-to-Xcode-26.0> - This is the simplest supported path when the error explicitly names the required Xcode version.
- Use a .NET for iOS workload version that supports Xcode 27.0
- Each .NET for iOS workload requires a specific Xcode version.
- The exact supported Xcode version for a workload is listed in the release notes.
- If support for Xcode 27.0 has been released, install the matching workload set version.
- If Visual Studio is pointing to an old or removed Xcode path, reset Xcode selection on the Mac
- Delete these files if they exist:
-
~/Library/Preferences/Xamarin/Settings.plist -
~/Library/Preferences/maui/Settings.plist
-
- Then either:
- run
xcode-select --switch ..., or - set
DEVELOPER_DIRto the intended Xcode path.
- run
- Delete these files if they exist:
Important details for this case:
- The installed CLI workloads shown in
dotnet workload listare 27.2.11039/11.0.100, but the error mentions 26.0.11017. That indicates Visual Studio is building with an older .NET for iOS toolchain than the one shown in the command-line output. - Updating macOS and Xcode alone can trigger this problem because newer Xcode versions often require matching newer workloads.
- Using a different Xcode version than the one required may work in limited cases, but it is not supported.
- As a temporary workaround only, the Xcode version check can be skipped by setting this in the project file:
This is not a supported long-term fix.<ValidateXcodeVersion>false</ValidateXcodeVersion>
For immediate debugging reliability, the lowest-risk option is to install Xcode 26.0 alongside Xcode 27.0 and switch to it when building this project.
References: