Hi! I understand you're having trouble buying tickets through the First Bus app. To help you better, could you tell me if you're seeing any specific error messages during the purchase process? Also, what payment method are you using (credit card, debit card, Apple/Google Pay)?

In the meantime, here are a few steps you can try:

1. Make sure you have a stable internet connection on your Windows device.
2. Try using a different payment method or card if possible.
3. If you use a card, check that there are sufficient funds and that the card is authorized for online payments.
4. Sometimes, previous declined payments can block the card temporarily; in that case, clearing that up with your bank can help.
5. If you’re using Apple Pay or Google Pay, ensure those apps are up to date and set up correctly on your device.
6. Try purchasing the ticket again after restarting the app or reinstalling it to ensure your app is up to date and not holding any cached errors.

If you’ve already tried these or still face issues, let me know any error details you get, and I can guide you further!

Also, you can visit this page for more info on payments not working:
https://www.firstbus.co.uk/bristol-bath-and-west/help-and-support/why-did-payment-not-work-0 1

Are you satisfied with these suggestions, or would you like me to help you with something else?