Build an Application: Step-by-Step #8 Exercise to Accompany Interfaces 101

Question

I am unable to execute "Step-by-Step #8 Exercise to Accompany Interfaces 101" because the W_W1731SAVehicleSummary interface displays the following message: 
 Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error at function a!gridField [line 335]: A grid component [label="W1731sa Maintenance"] has an invalid value for "columns". A grid column [label="Modified"] has encountered an error. Expression evaluation error at function 'user' [line 474]: [InvalidUserException]

Vyshnavi Naripeddi · Accepted Answer

Based on the [InvalidUserException] error, it seems that the provided username is NOT NULL , but the specified user does not exist in Appian. If the username is NULL , the error would have been " Expression evaluation error at function 'user': Null argument not allowed " 
 To prevent this issue, you can use the a!usernametaken() function to verify if the username exists before calling the user() function. 
 Could you share the code snippet of the a!gridColumn() configuration where you're facing the issue?

Vyshnavi Naripeddi · Answer

Hi jacobhbassett 
 As you are the only user and no others users mentioned in the created by column were active, I suggest you to follow the same approach that I have mentioned above.