Your browser requests permission when you first launch Playkey
An error is possible if you’ve disabled external-app launch.
But this can be fixed:
Create a new profile in the browser or restore its settings to default.
1. Close the browser.
2. Go to this location: For Yandex: C:\Users\[USERNAME]\AppData\Local\Yandex\YandexBrowser\User Data Substitute your username for [USERNAME].
3. Open the Local State file with Notepad (or notepad.exe).
4. Press Ctrl+F, find the line with playkey:true or playkey:false and delete it. Then save and close the file.
5. Launch the browser. Go to http://playkey.net/ and try launching the game again.
6. When opening playkey://* links, a window with a request for external protocol will appear again. Put a check in the box next to Apply to All Links of This Type field and click Launch App.
Open the menu select Settings and click on the "“Contents”" tab or enter the following command into the address bar: about:preferences#content. In the ““Pop-ups”" section, click on the Exceptions button, add http://playkey.net/ to the list of allowed sites, and save changes.