Rebalance failure during 4.1 -> 5.0.1 upgrade

Following the documentation for for upgrading 4.1 -> 5.0.1 and my rebalances keep failing due to this error:

Rebalance exited with reason {unexpected_exit,

   Rebalance exited with reason {unexpected_exit,

I’m able to restart the rebalance and continue but it’s hindering the upgrade process. The failures are occurring every 5 minutes.

I’ve started an upgrade from 4.1 -> 4.5.1 instead, and I’m not getting any rebalance failures.