nominal value not declared in header, read Token[X], line Y. I keep getting this popup on my Weka

Question

@relation WILEligibilityPerFaculty

@attribute YesFPW [Yes-Engineering,Yes-Computing&Informatics,Yes-HumanSciences,Yes-ManagementSciences,Yes-Health&AppliedSciences,Yes-NaturalResources&SpatialSciences] @attribute NoFPW [No-Engineering,No-Computing&Informatics,No-HumanSciences,No-ManagementSciences,No-Health&AppliedSciences,No-NaturalResources&SpatialSciences]

@data

Yes-Engineering Yes-Engineering Yes-Engineering No-Engineering No-Engineering No-Engineering No-Engineering Yes-Engineering Yes-Engineering No-Computing&Informatics, No-Engineering

Answer 1

If I understand your intent correctly, you actually have one attribute, not two. That attribute is FPW and can have the value of "Yes..." or "No...".

I've rearranged your data below and it loads into Weka correctly.

@relation WILEligibilityPerFaculty

@attribute FPW {Yes-Engineering,Yes-Computing&Informatics,Yes-HumanSciences,Yes-ManagementSciences,Yes-Health&AppliedSciences,Yes-NaturalResources&SpatialSciences,No-Engineering,No-Computing&Informatics,No-HumanSciences,No-ManagementSciences,No-Health&AppliedSciences,No-NaturalResources&SpatialSciences}

@data

Yes-Engineering 
Yes-Engineering 
Yes-Engineering 
No-Engineering 
No-Engineering 
No-Engineering 
No-Engineering 
Yes-Engineering 
Yes-Engineering 
No-Computing&Informatics 
No-Engineering

But I may not be interpreting your intent correctly. It's possible that you want to know the department, and Yes/No. In this case, you should separate Department and Yes/No into separate attributes:

@relation WILEligibilityPerFaculty  

@attribute Department {Engineering, Computing&Informatics}  
@attribute YesNo {Yes, No}  
@data  

Engineering,   Yes
Engineering,   Yes
Engineering,   Yes
Engineering,   No
Engineering,   No
Engineering,   No
Engineering,   No
Engineering,   Yes
Engineering,   Yes
Computing&Informatics,  No
Engineering,  No