Code:
IMyTextPanel panel = GridTerminalSystem.GetBlockWithName("panel") as IMyTextPanel; string selectedFont = panel.GetValue<string>("Font"); Echo(selectedFont); panel.SetValue("Font", "Red");
Trying IMyTextPanel also throw same error.

IMyTextPanel panel = GridTerminalSystem.GetBlockWithName("panel") as IMyTextPanel; string selectedFont = panel.GetValue<string>("Font"); Echo(selectedFont); panel.SetValue("Font", "Red");