Normally, miners on a proof-of-work blockchain like ethereum and test network Ropsten are required to manually upgrade their software in order to ensure the smooth continuation of a single chain.According to Hudson, the majority of miners on the Ropsten blockchain did not upgrade to the latest software, since the time of the hard fork caught many developers off guard. This has resulted in a split of the test network between those mining on the upgraded chain and those mining on the outdated chain.