How to use Skip Rules in Invoice approval workflow?

Summary:

We have a requirement on Project Invoice Workflow wherein if the Event Type is a value from a particular Lookup, then the Invoice should be Auto-Rejected. If it does not belong to that Lookup, then invoice should follow Approval Rule. We are trying to configure this via Skip rule but we are getting the error

"Error in evaluating parameter participant/skip condition in the routing slip"

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24C

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