[EtherCAT / RapidSetup] ENI Generation Fails with “Target of Invocation” Exception (FIPS Enabled)
Problem
RapidSetup successfully discovers EtherCAT nodes, but fails when attempting to:
- Generate ENI File
- Start Network
Error shown:
Exception has been thrown by the target of an invocation
Environment
- Software: RapidSetup (RSI)
- OS: Windows 11 (with security policies enforced)
- EtherCAT network: functioning (nodes discovered successfully)
Root Cause
Windows FIPS security policy blocks the use of MD5 hashing, which RapidSetup uses internally during ENI generation.
This is not an EtherCAT or communication issue—it is a Windows security restriction.
Solution
Fixed as of RMP version 11.0.5
For Older releases:
Option 1 — Disable FIPS Policy (Recommended)
Local Security Policy → Local Policies → Security Options →
System cryptography: Use FIPS compliant algorithms → Disabled
Restart RapidSetup (or reboot system), then retry.
Option 2 — Generate ENI Offline
- Generate ENI on a non-FIPS development machine
- Deploy the ENI to the production system
Notes / Gotchas
- Common on locked-down or IT-managed machines
- Error message is misleading
- Same setup may work on another PC without FIPS
Key Insight
Generic .NET exceptions can hide underlying security policy failures.