ES-8 with ES-3 & ES-6 issues

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Hi,
 I have an ES-8, an ES-3 that I had been using and just received an ES-6 in the  last few days.   I had no issues with the ES-8 and ES-3 leading up to this but now I am having some issues.
If I connect the ES-6 to either the ES-8 or ES-3 header it crashes the ES-3 module and presumably the ES-6 also.  When using it in VCV Rack it works until the crash and then VCV Rack won't respond either.    
This morning I ran audio and voltages through the ES-8 and ES-3 alone again fine with no crashes.   Then, I tried the ES-8 and ES-6 WITHOUT the ES-3 and it ran stable for a good hour or more without an issue.   I tried hooking up the ES-3 again and it crashed.

So summary:

ES-8 and ES-3 works
ES-8 and ES-6 works
ES-8, ES-3, ES-6 doesn't work.  

Thanks.

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I think I just replied to your email.