I was working on a script, which I'll post on later, to insert IPMI/iLO/iDRAC configs into my ESXi hosts. I would get an error the following error consistently no matter what I put into my IPMI object:
Exception calling "UpdateIpmi" with "1" argument(s): "A specified parameter was not correct.
At line:50 char:2
+ CategoryInfo : NotSpecified: (:) , MethodInvocationException
+ FullyQualifiedErrorId : VimException
The short answer, I had to 'null terminate' the properties in my IPMI object. I don't know 'why' I have to do this, but the vSphere API docs state that this is a requirement. Quite frankly, I had no idea what this meant.
To null terminate an object's property, you can simply do like so:
$MyObject = "" | Select Usefulproperty
$MyObject.Usefulproperty = ("Something" + $null)
I'll follow-up w/ a post of the script I put together to do this so that it makes more sense.