Couchbase 7.0 Beta rebalance error on functional 2-node server when 2 additional nodes are added

Just added 2 nodes to a 2-node functional cluster with a single CB bucket (replicas=1).

What could be the issue?

Then, clicking on rebalance again worked.

Many times I noticed that rebalance throws an error the first time, then after the 2nd or 3rd try it succeeds.

Hi,
Are you able to provide logs when the rebalance failure occurs? You can email them to me shivani.gupta@couchbase.com.