Validation Error: Invalid Bundle. The bundle at ... contains disallowed file 'Frameworks'

Solution 1:

Turns out the error is related to using Swift (both the app and the extension make use of Swift).

For the app, I had to set:

Embedded Content Contains Swift Code: YES

and for the extension:

Embedded Content Contains Swift Code: NO

Xcode 8 and 9

Looks like this has been renamed to Always Embed Swift Standard Libraries in Xcode 8 and 9. So, for the app:

Always Embed Swift Standard Libraries: YES

and for the extension:

Always Embed Swift Standard Libraries: NO

Solution 2:

The only solution that worked for me was to add this Run Script to the App Extension target:

cd "${CONFIGURATION_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}/"
if [[ -d "Frameworks" ]]; then 
    rm -fr Frameworks
fi

Source: https://github.com/CocoaPods/CocoaPods/issues/4203