Stuck in a loophole of stata generating r(111) error on its own generate residual prediction

[Alvin Kan]

I am currently trying to undergo a check on Endogeneity using the Hausman test with my dataset variables, however when i try to use the Hausman build in function after i have estimated both OLS model and 2sls model. It just couldn't recognize the estimate variable from the OLS model it just created and result as estimation result resols not found r(111); what have i potentially done wrong or how can i solve that?

[Andrew Musau]

Show us the exact commands that you ran and the resulting output. Copy and paste this directly from the Results window.