Hello @Simon_Pera
Unfortunately, this error is not available in the cluster log yet. It is only available in the deployment log for the moment.
I think your cluster is close to the limit of resources, and the update of the cluster was failing when your applications were running but succeeded when the applications were paused.
Indeed, if you want to be able to allocate more nodes in your cluster, you have to change the max number of instances in the cluster settings
Regards