使用MvvmCross模板创建的Xamarin.iOS项目无法打开Storyboard

I’ve run into this exact issue with Visual Studio for Mac preview builds and MvvmCross templates before—total buzzkill when you’re ready to dive into building your UI! Let’s walk through the fixes that have worked for me and other developers:

Step 1: Wipe Corrupted Build Artifacts (Most Likely Fix) #

The error points to an auto-generated Xcode project file in the obj/Xcode/0/ directory, which often gets corrupted during initial template setup—especially in preview IDE versions. Here’s how to reset it:

• Close Visual Studio for Mac entirely (don’t just minimize it).
• Navigate to your iOS project folder (/Users/username/Desktop/MyProject.iOS/).
• Delete the entire obj and bin folders—these are temporary build files, so deleting them is completely safe.
• Reopen Visual Studio, load your solution, and run a Full Rebuild (right-click the solution > Rebuild All). This will regenerate the Xcode project files from scratch, which should resolve the parsing error.

Step 2: Update MvvmCross Templates #

Older MvvmCross templates might not be compatible with VS for Mac 7.4 Preview. Let’s ensure you have the latest version:

• Open Visual Studio for Mac, go to Extensions > Manage Extensions.
• Search for "MvvmCross" in the gallery, and install any available updates.
• Try creating a new MvvmCross iOS project with the updated template—sometimes the initial project creation in preview IDEs leaves broken files behind.

Step 3: Address IDE Preview Bugs #

Since you’re using a preview build (7.4 build 1026), this could be a known issue with Xamarin’s Xcode project generation:

• Check if a newer preview build of VS for Mac is available—updating might patch the bug.
• If updating isn’t an option, try rolling back to the stable 7.3 version temporarily to see if the issue disappears (preview builds are great for testing, but they can have these kinds of kinks).

Step 4: Manually Inspect the Xcode Project File (If All Else Fails) #

If the above steps don’t work, you can take a look at the corrupted .xcodeproj file:

• Right-click your iOS project in VS for Mac > Show in Finder.
• Navigate to obj/Xcode/0/MyProject.iOS.xcodeproj, right-click it > Show Package Contents.
• Open the project.pbxproj file in a text editor. Look for malformed entries, missing brackets, or strange characters—these are often what cause parsing errors. If you spot something obvious, fix it (though deleting the obj folder and rebuilding is safer than manual edits here).

Pro Tip: When working with preview IDEs and MVVM frameworks, it’s smart to check the MvvmCross GitHub issues page—other developers might have reported the same problem and shared specific workarounds for your VS version.

内容的提问来源于stack exchange，提问作者Mark Reynolds