There was a small bug regarding uncle blocks, an update was released for this and deployed on pools before it affected any users.
No fork or any network downtime occurred. If your node is crashing, it's because you are not running this update.
Please update to the latest binaries and join the ubiq slack to stay updated.
Version v1.5.7 Main
https://github.com/ubiq/go-ubiq/releases/tag/v1.5.7http://slack.ubiqsmart.com/