application defined exception - no idea what is wrong

Question

can somebody help me out with this error

Project1.exe faulted with message: 'application-defined exception (code 0xc0000008) at 0x7c90e4ff'. Process Stopped. Use step or Run to continue.

Using Delphi 7 on Win XP. Installed are ony default original Delphi 7 components. I have only a button and opendialog component on my new fresh project. I am using just one line of code in ButtonClick procedure

OpenDialog1.execute;

when this warning on picture occurs. Open dailog shows up for milisecond then Delphi error is reported before I can choose anything from open dialog.

What could be wrong? This behaviour is new, because I used opendialog before without problems.

TIA

P.S. Program runs OK outside of Delphi IDE.

P.P.S. I deinstalled GExperts, DelphiSpeedUp but problem remains.

Answer 1

Looking around online, I see that this error seems to happen every now and then. I don't know the real reason, but it seems to be related to the debugger. I'd guess it is some kind of obscure debugger bug that only happens when many different things come together.

FWIW, I've seen reports from D4 to D7 and even D2006. It seems to be gone in higher versions, although that is not sure.

The more reports I see, I notice it always seems to happen in the Delphi debugger. More evidence that it is the debugger, IMO. If that is the case, there is not much you can do.

Answer 2

Your problem could be an Explorer addin that is throwing an exception.

It could be something that adds things to the file context menu, like Tortoise SVN (as an example, I'm not saying that's the culprit), or it could be something creates previews for files or even a trojan or adware.

The file open dialog uses the same code as Explorer to display the file list, so any add in that you have for explorer is also loaded/used for the file open dialog. In explorer, it might throw the exception but not kill anything, but in your program (whilst running in the debugger) you can see it.

How to fix it? Try uninstalling any explorer addins that you know about... If that doesn't work, maybe do a scan for adware and trojans.