SAS notifies that invalid reference value

[LarissaW]

As the photo showed, I was running proc phreg for a cox model, when I used proc freq to check the variable 'cig1rp', it was normal. However, when I put it in the multivariable model, SAS always notified that the reference value is invalid. I have no idea where the problem is.

[PaigeMiller]

Is there a format applied to variable CIG1RP?

What does PROC CONTENTS say for this variable regarding the presence or absence of a format? Please run PROC CONTENTS on the data set used in PROC PHREG and show us the (relevant parts of the) output.

Corrected: Replaced PROC FORMAT with PROC CONTENTS

[Quentin]

This support note has some suggestions:

https://support.sas.com/kb/61/382.html

But agree with Paige, first step is probably to run PROC CONTENTS to make sure that variable does not have a format attached.