I'm trying to pay milestones on fixed price contracts for two separate freelancers. I've tried in different browsers, cleared my cache. It just sits on "Loading" forever when I try to send payment. It looks like it might be trying to authorise the computer.
I checked and it looks like there is a known issue and our engineers are working on fixing it already. I'll have somebody reach out to you directly via a ticket and keep you updated about the progress.
Sorry about the inconvenience.