AI-Scripts 4.1R1 should not be used with EX4300-VC. This only affects VC deployment. As a result of a JUNOS bug, AI-Scripts will not be able to properly set up node-to-node communications, particularly between the backup and primary nodes. AI-Scripts will then continue to detect the issue, and the effect will cause the VC to split.
Avoid using AI-Scripts 4.1R1 with EX4300-VC until this has been fixed.