iOS crash report "unexpected start state" exception? iOS crash report "unexpected start state" exception? ios ios

iOS crash report "unexpected start state" exception?

Just call your function in background thread:

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{    // here, call your function    dispatch_async(dispatch_get_main_queue(), ^{        // do updates on main thread    });});

The above crash happens when you try initializing a NSAttibutedString with html content from any other thread than the main thread.

So the solution here is to make sure the above NSAttributedString initialization is always called from the main thread.

DispatchQueue.main.async {    let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [.documentType: NSAttributedString.DocumentType.html]    let htmlString = try? NSAttributedString(data: htmlData, options: options, documentAttributes: nil)}

Quoting the documentation:

The HTML importer should not be called from a background thread (that is, the options dictionary includes documentType with a value of html). It will try to synchronize with the main thread, fail, and time out. Calling it from the main thread works (but can still time out if the HTML contains references to external resources, which should be avoided at all costs). The HTML import mechanism is meant for implementing something like markdown (that is, text styles, colors, and so on), not for general HTML import.