If you are trying to take a payment via the 'Charge to room' option and it is not working, here is what you need to check...
Is the amount you're trying to charge to the room equal to the full order value or only part of the value? If it is a partial amount (i.e. not the total cost of the order) you will not be able to charge to a room. It must be the full total so that the correct Revenue allocations can be accounted for against the payment.
Have you checked if the Opera/Guestline interface (or any other PMS we integrate with) is down by heading to Settings > Integrations > Manage integrations > Click on the integration in question? If it is, you will need to restart it and contact your IT support team for initial assistance.
For Opera:
Check in Opera that bookings have the No Posting box unticked.
If the relay is showing as ‘Ok’ and the room is checked in on Opera, but you are unable to charge to room because it is greyed out and cannot be selected, this is likely because either the room has no post ticked or the room will be past its credit limit. Both of these settings are managed in Opera.