Hey Simon, Testnet is currently having extremely high block times because a ton of hash power was pointed at it last week and then was pulled away. This may be the cause of the error message you received. Because of the problems, testnet will be reset either later this week or next week.
Hey Simon, The problem was fixed in the latest release a couple weeks ago. You can get v1.3.0 here: https://github.com/decred/decred-binaries/releases Testnet was reset in the latest release so you can delete the old testnet2 chain data as well. dcrd will download the new testnet3 chain in v1.3.0.
Now, only version 1.2.1 wallet can be downloaded from the official web site(see https://www.decred.org/downloads). Will version 1.3.0 one be uploaded to there? Will version 1.2.1 testnet be reset?
Testnet2, which is what v1.2.1 uses, will not be reset. You can get v1.3.0 from the Decred Github page which I linked in my previous post. v1.3.0 is currently a release candidate, so when it becomes an official release the official website will be updated with the new download link.