The Weather Forecasting Forum

Need help to correct this after plotting data. See attachment

Hi,
A more detailed description of how this error occurred would be most helpful.
Chris

Thanks, Chris. It occurs when I plot the data and it recur several times as I work on the map.

Eddie

After retrieving data, I plot data on map and at the same time get the following error message: "Access violation at address 004FEFED in module 'digatmos.exe." Read of address 000003B6.

I click [OK] an proceed to draw isopleths. As soon as I do, the plotted data vanishes.

Help please!

What is the version of DA that you are using?

From what data source has this data been downloaded?

Does this happen for both surface and upper air data plots?

Source: metar from COD radiosonde from COD radiosonde from NIU

VERSION: 3.50a Professional

Both upper air and surface this issue occurs

REH_golf wrote: Mon Aug 18, 2025 5:21 pm Source: metar from COD radiosonde from COD radiosonde from NIU

VERSION: 3.50a Professional

Both upper air and surface this issue occurs

Other things that could help someone troubleshooting this:

1. When did this start occurring?

2. If it's a new problem, did you have any software or hardware changes between when it worked without a problem, and when you started getting this error?

Finally, there was a report of on these forums for a much older version with a similar problem behavior when plotting here:

viewtopic.php?p=5999&hilit=violation#p5999

A person responding to that problem report fixed it on his PC with a DA reinstall. But that didn't work for the original poster.

While I can't debug specific instances of this without more detail, I will tell you all that I have noticed this issue when various display monitors are enabled or disabled on a computer (primary or secondary ones). This is an issue having to do with the Delphi language that Digital Atmosphere is compiled in. You may want to check if this is an issue in your case.

The problem occurs when Windows sends internal WM_DISPLAYCHANGE messages to notify applications, but Delphi's Visual Component Library lacks the multi-monitor awareness and device context management found in newer compilers, causing forms to reference invalid screen positions or graphics handles to become corrupted.

I am looking at testing some updates that can intercept display change notifications and perhaps prevent this. As some of you may know I am in the process of writing a completely updated and modernized version of Digital Atmosphere and ultimately this will be the final workaround for it.

Tim