I'm trying to sync the blockchain but it gets stuck, I've downloaded a fresh chain. It just says constantly that Sync data returned unknown top block. If I can't sync the blockchain, am I able to send money with my wallet? I tried to send some, it says money successfully sent, but I have never received it on an exchange. I've used Payment id.

EDIT: I've redownloaded a fresh copy of the blockchain and my transaction has never gone through. How can I send monero with my client behind firewall? I can't open ports