Question Why do you need 'Convert Colors' fixup, rather than 'Map spot and process colors' fixup that failed?

[scherz0]

I don't understand mrserge's answer. Please explain in Simple English like I am 9 years old.

In this case you must choose different fixup to do that, because that second spot color is something that giving an error [emphasis mine]. In this example I will show you how to convert spot color to specific destination CMYK. You can modify your existing Spot color conversion fixup.

1. "that second spot color is something that giving an error" — What does this mean???
2. Why exactly did the 'Map spot and process colors' fixup fail in Adobe Acrobat Pro DC?
3. Why did mrserge need the 'Convert colors' fixup instead?

 

[mpo]

See image 3.

Adobe Acrobat didn't understand the color smart_pdf. It was expecting a value like the first spot color 'Pantone 321 U'.

The convert colors process changed smart_pdf to a value of blue the printer could understand.