I had an issue with the Ethereum Mist wallet never finishing syncing the blockchain. Mist just kept downloading “chain structure” for two days, always stuck a couple of hundred blocks behind the most current one.

Here’s how I fixed it:

  1. Close Mist first if it’s running.
  2. Download the latest version of Geth and extract it to somewhere like C:\Geth (https://geth.ethereum.org/downloads/)
  3. Run CMD.exe (Command Prompt, the black terminal window in Windows) as Administrator (right-click -> Run as Administrator)
  4. Change directory to where you extracted Geth:
    CD C:\Geth
  5. Run the following command to start syncing the blockchain using the light syncmode:
    start geth –syncmode light –cache 512
  6. It should now start syncing. After a while (how long varies), you will notice it reaches the current block and becomes less active. You should now be able to run the Mist wallet without issues again.
  7. Download and run the latest Mist wallet to avoid other bugs/issues (https://github.com/ethereum/mist/releases)

Hope this helps someone out there with the same annoying issue!