Looks like a corrupt database (did the computer crash or lose power while Linda was running maybe?). You could try deleting the database and let it resync.

Alternatively, rename your AppData\Roaming\Linda folder (or remove it, making sure you backup your wallet.dat first!), open the Linda wallet (to allow it to recreate the folder), close it again then restore/copy your wallet.dat to the new AppData\Roaming\Linda folder. You may also want to backup/restore your Linda.conf file.

You could also try running the Linda wallet on another computer. Just copy your wallet.dat file from the first computer.