DC Analysis

I am trying to run a Probe DC Analysis on a circuit, but whenever I try to start the run, I receive a Source Not Found error that references NONE. How do I get past this?

To run a Probe analysis, you must first go into the standard DC analysis. Access the DC Analysis Limits dialog box. There are two fields that must be filled in: Input 1 and Input 1 Range. The PART attribute of either a voltage or current source that is present in the schematic must be entered into Input 1. The default for Input 1 is NONE, which is the name of the source it is searching for if you go to Probe first. Input 1 Range is just the range that the source is to be swept over. Input 2 can be left at NONE if only one source is to be swept. Exit the analysis. Run Probe DC Analysis again, and it should run fine.