Hi there! I understand your Circle app is showing a "sign in failed" message with a blank page when you try to open it. Just to get a clearer idea—are you trying to sign in on the mobile app or through a browser on your Windows device? Also, have you been able to log in successfully before, or is this the first time seeing this issue?

Meanwhile, here's a general approach we can try to fix the problem:

1. Clear Cache and Cookies: Since you're on Windows and possibly using a WebKit-based browser, try clearing your browser’s cache and cookies. Sometimes corrupted data can cause loading or login errors.

2. Check Internet Connection: Make sure your internet connection is stable. Try opening another site to confirm.

3. Update the App or Browser: If you're using the installed app, check if there’s an update available. For browser users, ensure the browser is updated to the latest version.

4. Restart Device: Restart your Windows system. This helps clear temporary glitches.

5. Login Credentials: Double-check your username/email and password. If you’re uncertain, try resetting your password from the Circle app or website.

6. Try Another Browser or Device: To isolate the issue, try signing in from a different browser like Chrome or Firefox or from another device.

7. Disable Browser Extensions: If you are signing in through a browser, temporarily disable any browser extensions that might interfere with page loading.

If these steps don’t resolve the issue, there may be a deeper issue with your account or app installation. In that case, contacting your community admin or Circle support might be necessary, as they can check if there’s an account-specific problem or server-side issue1.

Let me know what you’ve tried already and how you’re accessing the app so I can help you further!