Hello! I understand your O2 Venue App is closing about 15 seconds after you open it on your Windows device using WebKit. Let's address this step-by-step.

First, just to confirm:
- Are you accessing the O2 Venue App via a web browser or is it a standalone app installed on your machine?
- Have you tried restarting your device already?
- Did this issue start suddenly after an update, or has it been ongoing since you first used it?

In the meantime, here are some general troubleshooting steps that often help with app crashes, especially on Windows via browsers:

1. Clear Browser Cache and Cookies: Since you use WebKit (which is used by browsers like Safari, but on Windows it might be different), clearing your browser's stored data may resolve conflicts causing the app to crash.
- Go to your browser settings > Privacy or History > Clear browsing data > Select cache and cookies > Clear.

2. Try a Different Browser: If you are accessing via browser, try opening the O2 Venue App in a different browser (like Chrome, Edge, or Firefox) to see if the issue persists. Sometimes browser-specific issues cause these behavior quirks.

3. Disable Browser Extensions: Some browser extensions can interfere with web apps. Try disabling them temporarily to check if that helps.

4. Update Your Browser: Ensure your browser is updated to the latest version for compatibility.

5. Check for Windows Updates: Sometimes OS updates fix underlying issues causing app crashes.

If you are using a standalone O2 Venue App (installed program), please try:
- Restart the app after uninstalling and reinstalling it. A fresh install can clear corrupted files causing crashes.
- Check for any app updates available and install those.

Please let me know what you’ve already tried or if you see any error messages when the app closes. This info will help me guide you better.

Are you satisfied with these initial steps? If not, we can explore more advanced fixes.