It takes a while for custom dimensions to collect enough valuable data to be used in Google Analytics. This process can take 24-48 hours or even longer depending on the data complexity and volume. Despite setting up the dimensions and calling the setUserProperties method, it may require some patience until you’ve got enough data for Google Analytics to use. In addition, remember that these custom dimensions will only start collecting data after they’ve been set up – they won’t have data retroactively. So, if it’s been some days but there’s not enough activity or events in your app to generate significant data, you might still encounter this message. I’d suggest continue the user properties setting with Firebase, check if everything is set correctly, and be patient for the data to be accumulated.