Modular Hydraulics cannot be used with electrical system v1

Version: 1.2.7.0

Frequency: Consistently

Severity: High

Bug description:
The new modular hydraulics system cannot be used with electrical system version 1.
Any hydraulic pump or valve circuit will not be detected by the hydraulics systems and will lead to an error.
The only solution is to migrate to electrical system version 2, but for which reason?
This is not precised in the SDK documentation.