Can you provide a screenshot or an error message?

Do you have automatic running enabled? If so try re running manually. I don’t think it works every time though.

Hmm. I've looked at the website again and actually there isn't a mention of specific APIs. It just says "Technical and App Store labs" and "Design Labs". So I guess I'll just close this question.

@KingOfTheEmpre Ok then can you try changing the playground's target platform to macOS like how it is suggested in this stackoverflow answer?

Ok @KingOfTheEmpre can you check if the target platform of the playground is macOS? If the target platform's something other than macOS try changing it to macOS like it is suggested in this stackoverflow answer. Perhaps that will work.

shoot. multiple comments. Thought the forum deleted my comment, turns out I was wrong. Anyways, didn't mean to spam you, sorry. ;)

@KingOfTheEmpre If the above solution doesn't work, consider using the Swift Playgrounds app on the macOS app store. It's not a perfect replacement for XCode Playgrounds (for instance, playgroundbooks are only available on xcode playgrounds), but if xcode playgrounds is too buggy it might be worth it. P.S. Note that the swift playgrounds app also has a bug which makes playgrounds crash (specifically when using SwiftUI). The solution to that bug is to turn off the "enable results" option for that playground ;)