The user-defined properties routine was invoked for gas viscosity but this generic error message exists. Either choose a different model or correct

Hello,
I modified viscosity from usr_properties.f and I got the following error “The user-defined properties routine was invoked for
gas viscosity but this generic error
message exists. Either choose a different model or correct”
what dose it mean?
1dheatconduction_2022-06-12T194626.399996.zip (354.6 KB)

Solved.

Based on the following sentence in the user_properties.f
“! if using this quantity then remove definition of ier
ier = 1:”
ier=1 must be removed