edit: resolved. I'm not sure what the root cause was here but once the blockchain caught up to the current best height getblock calls began functioning properly again. I'll edit again if this issue recurs and I am able to track down the issue.
Good to hear that the issue is solved. I think your wallet wasn't done synchronizing with the network. Your getinfo output showed that you only had 237209 blocks while currently the network is at 601597 blocks.