Fix CocoaPods Error: Unable to Find Compatibility Version for Object Version '70'

Problem Description

When adding a Share Extension to a Flutter iOS project in Xcode 16, running pod install frequently fails with the error:

CopyArgumentError - [Xcodeproj] Unable to find compatibility version string for object version `70`.

This occurs because Xcode 16 automatically updates your project's configuration to use object version 70 when certain new features (like adding Share Extensions or using Xcode 16-specific functionality) are implemented. However, CocoaPods versions older than 1.17 don't recognize this version string.

Common scenarios triggering this error:

• Adding a new Share Extension target
• Using Xcode 16-specific features like "New Folder" in Project Navigator
• Working with Flutter projects where CocoaPods manages dependencies

Affected environment:

• CocoaPods: 1.16.2 (or older)
• Xcode: 16+
• Flutter projects with iOS targets

Solutions

Solution 1: Change Project Compatibility Version via Xcode UI

The most reliable fix involves reverting your project's compatibility settings:

1. Open your project in Xcode
2. Select your project name in the Project Navigator
3. Under the PROJECT section (not TARGETS), locate Project Format
4. Change from Xcode 16.0-compatible to an older compatible version like Xcode 14.0-compatible
5. Save changes and close Xcode
6. Run:

   pod install

Solution 2: Edit project.pbxproj Manually

If Xcode doesn't resolve the issue, manually edit the configuration:

1. Right-click your .xcodeproj file → Show Package Contents
2. Open project.pbxproj in a text editor
3. Search for:

   objectVersion = 70;

4. Change 70 to a compatible version (typically 60):

   objectVersion = 60;

5. Optionally update compatibilityVersion:

   compatibilityVersion = "Xcode 14.0";

6. Save and run:

   pod deintegrate
   pod install

Solution 3: Convert Folders to Groups

If you've used Xcode 16's "New Folder" feature, which forces version 70:

1. In Xcode Project Navigator:
   • Right-click any Folder (blue icons)
   • Select Convert to Group
2. Repeat for all folders until only groups (yellow icons) remain
3. Verify objectVersion reverted to 60 in project.pbxproj
4. Run:

   pod install

Why This Works

• Xcode 16 introduces new project formats (version 70) that older CocoaPods versions don't support
• Reverting to version 60 maintains compatibility with existing dependencies
• Converting folders to groups eliminates Xcode 16-specific features that trigger version upgrades
• These changes don't affect functionality—only how Xcode organizes project metadata

Prevention Tips

1. Always back up project.pbxproj before editing
2. For new projects, check compatibility version before adding extensions:

   grep 'objectVersion' YourProject.xcodeproj/project.pbxproj

3. Update CocoaPods regularly:

   sudo gem update cocoapods

4. Avoid "New Folder" in Xcode 16+; use "New Group" instead

Compatibility Notes

Component	Supported Version
CocoaPods	Versions before 1.17
Xcode	16+
Works with	Flutter, React Native, native iOS

Still encountering issues? Ensure all folders have been converted to groups and that your Podfile correctly references both targets:

target 'Runner' do
  use_frameworks!
  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
end

target 'Share Extension' do
  # Add shared pod dependencies here
  pod 'SharedPod'
end