I have the same error earlier with my blockchain account. I tried to log out and log back in and I get the same message in red saying chain head not found and my account balance is not showing just 0.00 but now its fine.
After restarting my computer and login in again I got all my former dashboard this is the second that happens to my dashboard the first time was months ago but I knew it is just a bug and I just need to login again to regain my dashboard,hopefully it will not happen again
i ever experienced this, you just need to wait,it'll recover itself very soon,and if you're forcing to send when this error happen, your transaction will show not found in blockchain but if you'd check it in another wallet explorer like blockrail it'll appear