copy and paste this script in framework projects to get the correct directory structure.

step by step:

1. In project screen go to menu, press Editor, press “Add Build Phase”,

press “Add Run Script Build Phase”, leave it last.

2. Change script name into “Multiplatform Build” by double clicking the “Run Script” title.

3. Paste the contents of this file into the blank rect. Leave it as /bin/sh

4. Check the result is indeed multi platform from terminal:

xcrun lipo -info <Framework_name>

# Sets the target folders and the final framework product.
FRAMEWORK_NAME=YourLibraryName
FRAMEWORK_VERSION=1.0
FRAMEWORK_CONFIG=Release

# Install dir will be the final output to the framework.
# The following line create it in the root folder of the current project.
INSTALL_DIR=${PROJECT_DIR}/Products/${FRAMEWORK_NAME}.framework

# Working dir will be deleted after the framework creation.
WORK_DIR=build
DEVICE_DIR=${WORK_DIR}/${FRAMEWORK_CONFIG}-iphoneos/${FRAMEWORK_NAME}.framework
SIMULATOR_DIR=${WORK_DIR}/${FRAMEWORK_CONFIG}-iphonesimulator/${FRAMEWORK_NAME}.framework

xcodebuild -configuration "${FRAMEWORK_CONFIG}" -target "${FRAMEWORK_NAME}" -sdk iphoneos

echo "Build simulator"
xcodebuild -configuration "${FRAMEWORK_CONFIG}" -target "${FRAMEWORK_NAME}" -sdk iphonesimulator

# Creates install directory if it not exits.
if [ ! -d "${INSTALL_DIR}" ]
then
mkdir -p "${INSTALL_DIR}"
fi

# Creates headers directory if it not exits.
if [ ! -d "${INSTALL_DIR}/Headers" ]
then
mkdir -p "${INSTALL_DIR}/Headers"
fi

# Remove all files in the headers diectory.
for file in `ls "${INSTALL_DIR}/Headers"`
do
rm "${INSTALL_DIR}/Headers/${file}"
done

# Remove binary library file.
rm -f ${INSTALL_DIR}/${FRAMEWORK_NAME}

# Copies the headers files to the final product folder.
if [ -d "${DEVICE_DIR}/Headers" ]
then
for file in `ls "${DEVICE_DIR}/Headers"`
do
cp "${DEVICE_DIR}/Headers/${file}" "${INSTALL_DIR}/Headers/${file}"
done
fi

# copy nibs to bundle,then copy bundle to final folder
BUNDLE_DIR=${DEVICE_DIR}/${FRAMEWORK_NAME}.bundle

if [ -d "${BUNDLE_DIR}" ];then
if ls ${DEVICE_DIR}/*.nib >/dev/null 2>&1;then
                    rm -rf ${BUNDLE_DIR}/*.nib
                    cp -rf ${DEVICE_DIR}/*.nib ${BUNDLE_DIR}
                    fi
                    rm -rf "${INSTALL_DIR}/${FRAMEWORK_NAME}.bundle"
                    cp -R "${BUNDLE_DIR}" "${INSTALL_DIR}/${FRAMEWORK_NAME}.bundle"
                    fi
                    
                    echo "Merge with simulator"
                    # Uses the Lipo Tool to merge both binary files (i386 + armv6/armv7) into one Universal final product.
                    lipo -create "${DEVICE_DIR}/${FRAMEWORK_NAME}" "${SIMULATOR_DIR}/${FRAMEWORK_NAME}" -output "${INSTALL_DIR}/${FRAMEWORK_NAME}"
                    
                    rm -r "${WORK_DIR}"