Hello, I am having an issue. While on approach for an ILS, the FMC comes up with an error like this. APP ERROR/ FREQ DO NOT AGREE or something like that. This usually happens just after I intercept the localizer. I just clear out the error, and everything seems to work fine. I just don't like errors because it means I've done something wrong. Does anyone know what causes this error? FYI, It does'nt matter which rwy or airport. I have the latest Star/Sid's and the latest all in one nav download. I have the ILS Freq active in both Nav 1 and Nav 2 and the correct rwy set up in the FMC. Both A/P CMD are selected as well.All my 737's are doing this. The 747 seems ok. But it auto enters the freq. If anyone can chime in, please do.Thanks,Dan

Dan,This is due to the fact that the FMC gets the its course data from the latest AIRAC files whereas LOC and GS (and AP) get their data based on what is installed in MSFS (default or add-on scenery .bgl's). The magnetic variation of the later is a bit old and falls behind latest data. Just ignore.Best,Vangelis===================================== E. M. Vaos Precision Manuals Development Group www.precisionmanuals.com=====================================