I've had issues with the last two updates on AEM as a Cloud Service. The pipelines and deployments have failed, and the instance needs to be deleted and recreated manually.
The error says "Contact Adobe Support" although as this is a partner sandbox, support is limited. Just logging the error here in case others come across something similar.
Once recreating the pipeline, it builds ok, but fails at the deployment step. the error in the log appears to be
common.sh: line 268: state_publish: unbound variable
Once the instance is deleted and recreated, everything works fine