Compiling fails on Xcode 8

[dymx101]

When I tried to compile it on Xcode 8, the compiling fails, and here is the error description:

CodeSign /Users/xxx/Library/Developer/Xcode/DerivedData/YYY-devhhrztnwiafzdnbmqgugeublld/Build/Products/Debug-iphonesimulator/DownloadButton.bundle
cd /Users/ydong/Documents/codebase/YYY/YYY/Pods
export CODESIGN_ALLOCATE=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/codesign_allocate
export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"

Signing Identity: "-"

/usr/bin/codesign --force --sign - --timestamp=none /Users/xxx/Library/Developer/Xcode/DerivedData/YYY-devhhrztnwiafzdnbmqgugeublld/Build/Products/Debug-iphonesimulator/DownloadButton.bundle

/Users/xxx/Library/Developer/Xcode/DerivedData/YYY-devhhrztnwiafzdnbmqgugeublld/Build/Products/Debug-iphonesimulator/DownloadButton.bundle: bundle format unrecognized, invalid, or unsuitable
Command /usr/bin/codesign failed with exit code 1

Does anyone knows what's the going wrong?