
I have a working MSI installer that also checks a serial code entered by the user. So, the CustomAction DLL and basic interaction works perfectly!
I decided to add a label on the CustomerInfoForm (`SerialLabelError`) that would replace the MessageBox that would pop up in case the user entered a wrong serial code.
Problem is: I cannot get the CustomAction DLL to update the Label `SerialLabelError`! I tried various examples on the internet, using ActionData, but the MSI doesn't update the Text Control in the MSI.

How do I tackle this? The DLL returns ERROR_SUCCES on all functions that post data back, so the DLL functions seems to be sending the data correctly back to the MSI.
In the MSI, I added (using ORCA) an ActionData entry to the to the EventMapping table. The entry points to the CustomerInfoForm > SerialLabelError > Text Attribute. Exactly as suggested by the articles I red.
Please, could anyone help me out?

Thanks, Daniel
The piece of code in the DLL used to send data back is: