I've been running a full node since 2011, updating it as needed to the latest version. Recently, it stopped syncing beyond about 4 weeks ago. I decided to upgrade to the latest version, 0.91, so I uninstalled the old one and deleted all the blockchain data (everything in the blocks directory). Downloaded the 64-bit version, and launched it, only to receive this error:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2FyHU3GrS.png&t=663&c=PjMPCKocLxXvnw)
It creates a blk00000.dat file and an index directory within the blocks folder during this attempt. If I launch it again, then I get this error:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2FZf52Lwl.png&t=663&c=unI865Gv-1rMCg)
If I delete everything in the blocks folder again, I get the first error again.
What have I done wrong, and how can I fix it?