In Xcode, if you go to Window -> Organizer and then right-click on your archive, Show in Finder, right-click on the .xcarchive file and Show Package Contents, you'll see a folder labeled "dSYMs". Right click on the dSYM file and compress it. Then, you can upload the resulting zip file to the Crashlytics dashboard. When viewing your project in Crashlytics console, there's a tab labeled "dSYMs". Select that and then you can upload your zip file. Doesn't solve the error but makes Crashlytics usable