Final answer:
The first thing to check if no applications or RUM data appear in Dynatrace is network connectivity issues. This is because Dynatrace requires a stable network connection to transmit monitoring data successfully.
Step-by-step explanation:
If you do not see any of your applications or Real User Monitoring (RUM) data in Dynatrace, the first thing you should check is (a) Network connectivity issues. Before delving into other possible causes such as browser compatibility settings, data retention policies, or user access permissions, verifying network connectivity is fundamental. It is essential because Dynatrace, being a cloud-based monitoring solution, relies heavily on the network to send and receive data. An interruption in connectivity could prevent data from being transmitted to the Dynatrace servers, hence resulting in no data being displayed in your Dynatrace dashboard.