Go-Ethereum – Mist Couldn’t Connect to Node? See Logs for Solution

geth --fast has nothing to do with the connection to node, --fast is only telling geth to sync the block headers only and enough to perform transactions. A few latest blocks.

Wait until the node is fully synced.

--fast Enables fast syncing through state downloads

Update your system time to sync with an internet time server

In Windows: 1)Double click on the date&time displayed on the taskbar on the lower right hand corner of your screen 2)Click "Change Date and Time Settings" 3)Click on "Internet Time" tab 4)Check the box "Synchronize with an internet time server" 5)Chose a server (e.g. time.nist.gov) from the drop-down 6)Click "Update now" button 7)Re-launch Mist and let it finish syncing your node with the block-chain data from its peers before trying to send your transaction again

OS X: sudo ntpdate -u time.apple.com

Linux see: https://unix.stackexchange.com/questions/79112/how-do-i-set-time-and-date-from-the-internet

I had the same issue, so I tried Parity, which threw an error: "Your clock is not in sync. Detected difference is too big for the protocol to work: -2254ms. Synchronize your clock."

When I did the above, I was able to re-launch Mist, Parity, and the Ethereum Wallet client and my transactions could go through with any of those (after finishing syncing the node with the block-chain data from network peers)