augmented component-plus-residual plot help

[Brittany Bissell]

Currently running a linear regression model - attempting to test for linearity for my model: regress logKFFD VASOPRESSIN_12 MELD_S SOFA RACE NEPH_TO EGFR

My primary DV of interest if VASOPRESSIN_1. When I type in the following:
cprplot VASOPRESSIN_1, lowess

This returns...

VASOPRESSIN_12HRS^2 is collinear with VASOPRESSIN_12HRS

Am I missing something? I'm confused why it is demonstrating co-linearity with itself?

Any help would be great!!!!

[Carlo Lazzaro]

Brittany:
no wonder that a squared variable is collinear with its linear term.

[Brittany Bissell]

But the squared variable is being generated by STATA? It's not in my model or in my data at all.