LLDB crash

I downloaded new mac os big sur developer beta and Xcode has started crashing. when I open Xcode, it says xcode quit unexpectedly while using the libMainThreadChecker.dylib plug-in. my Xcode version is 10.3 and it was working perfectly fine on catalina

Since the first beta of Xcode 16, randomly when editing a SwiftUI view a crash report opens with the message PreviewShell quit unexpectedly. After that, annoyingly often the canvas fails to reload correctly, and shows this broken thing: The only way to get it working again is to restart Xcode, but it happens so often that it really impacts productivity. Does this happen to anyone else? If so, have you found a solution? I've already filed a report (FB14876223)

Latest Xcode 7.3 (7D1002)Since yesterday I got the same bug as described here:http://stackoverflow.com/questions/24125539/xcode-lldb-print-statements-fail-nsundomanagerhttp://www.openradar.me/search?query=15890965except that it even happens with NSString variables: po someString error: instance method 'URLEncodedString' has incompatible result types in different translation units ('void *' vs. 'NSString *') error: instance method 'URLDecodedString' has incompatible result types in different translation units ('void *' vs. 'NSString *') note: instance method 'URLEncodedString' also declared here note: instance method 'URLDecodedString' also declared here error: 2 errors parsing expressionI found a workaround for local variables (even though this problem is different):http://lists.apple.com/archives/xcode-users/2014/May/msg00088.htmlctrl-click on variable in local variables list and choose “print description” Printing description of someString: ipadwhich helps a little but cannot print more complex com

I have no idea what to do. I am building a weather app. I created a variable with the url and I know the url works but I need the data for the place the user types into the text field. So I concatenate my UITextField in the correct place in the url and I get this error in the log.fatal error: unexpectedly found nil while unwrapping an Optional value(lldb) here is my code:import UIKitclass ViewController: UIViewController { @IBOutlet weak var textfield1: UITextField! @IBOutlet weak var outputlbl: UILabel! @IBAction func findtheweather(sender: UIButton) { let url = NSURL(string: http://www.weather-forecast.com/locations/ + textfield1.text! + /forecasts/latest)! let task = NSURLSession.sharedSession().dataTaskWithURL(url) { (data, response, error) -> Void in if let urlcontent = data { let webcontent = NSString(data: urlcontent, encoding: NSUTF8StringEncoding) let websitearray = webcontent!.componentsSeparatedByString(3 Day Weather Forecast Summary:</b><span class=read-more-small><span