When entering a key value pair for the setCustomValue method for a ManagedObject in the vSphere UI, if the value is greater than 4000 characters then an error is shown that says "Method Invocation Result: InvalidArgument"
/var/log/vmware/vpxd/vpxd.log will also have the following log lines:
```
--> (vmodl.fault.InvalidArgument) {
--> faultCause = (vmodl.MethodFault) null,
--> faultMessage = <unset>,
--> invalidProperty = "value"
--> msg = ""
--> }
--> Args:
-->
--> Arg key:
--> "<customer_entered_key"
--> Arg value:
--> "<customer_entered_value>"
```
This occurs because there is a 4000 character limit on the client side that will throw an exception if the value is greater than 4000 characters.
VMware is aware of this issue and working to resolve this in a future release.