"Error connecting back to host app" in Safari 13

What radar did you file? Do you have the radar number handy? I'd like to see if this still reproduces.

I have similar problem with simple Safari Extension App.

After Safari has been running for some time. On `send()` (button click in popover) 'SFSafariApplication.getAllWindows' stops working and completion handler is never fired. Console shows 'Error connecting back to host app: NSCocoaErrorDomain, code: 4099'.

Edit: also 'SFSafariApplication.openWindow' not working after error

Tested on Safari Technology Preview - Release 91 (Safari 13.1, WebKit 14609.1.3) Mojave

SafariExtensionViewController.swift

    @IBAction func send(_ sender: Any) {
        self.count += 1
        SFSafariApplication.getAllWindows { (windows) in
            for window in windows {
                window.getAllTabs { (tabs) in
                    for tab in tabs {
                        tab.getPagesWithCompletionHandler { (pages) in
                            for page in pages ?? [] {
                                page.dispatchMessageToScript(withName: "test", userInfo: ["count": self.count])
                            }
                        }
                    }
                }
            }
        }
    }


    @IBAction func open(_ sender: Any) {
        SFSafariApplication.openWindow(with: URL.init(string: "https://google.com")!) { (window) in
            NSLog("opened")
        }
    }

script.js

document.addEventListener("DOMContentLoaded", function(event) {
     safari.self.addEventListener("message", function(event) {
        if (event.name === 'test') {
          console.log("Message from background received: ", event.message.count);
        }
     });
});

That's a known issue with Safari Technology Preview. It shouldn't affect Safari 13. Additionally, installing Safari 13 will cause this to work correctly in Safari Technology Preview. Sorry for the inconvenince here!