Dgraph v25.0.0-preview1

I saw a preview version for dgraph v25 was released. I tested it briefly and so far only found one issue:
In Ratel when navigating to the Cluster tab, the following error is briefly shown, before only a white screen persists (see image below). ACL is disabled for this cluster.

Also, did the on-disk data format change, so that an export and import is necessary for existing installations?