Error 41. Unsupported field in GetRTData

Occurs when not supported field was specified in GetRTData call:

GetRTData("EPSRank"); // EPSRank is not available from RT sources

Note that GetRTData is supported only for real-time data sources and in Professional edition only. If you attempt to call it without running RT data source or using AmiBroker Standard edition, it will quietly return Null value without displaying any error message.