DLL compilation problem


I have this old application which I created long time ago (more than 10 years) which calls few dlls. The application is fine but I tried today to compile one of the DDL apps I get this error (which already was compiled fine then)

Unresolved External GetDiskFreeSpaceExA in DriveInfo.obj

It has been years since last compilation and many templates were added since then to my Clarion 6.3.

I tried to create a new DLL with fresh structure but still getting the same error.

Any help is extremely appreciated.

This is the link-time error rather than the compile-time error, The entry for GetDiskFreeSpaceExA is in WIN32.LIB since C10. Before that it was in WIN32Ext.LIB. WIN32.LIB is adding to the link list automatically. WIN32Ext.LIB must be added to the project manually.

I brought WIN32Ext.LIB from Calrion 9 and extracted GetDiskFreeSpaceExA in a new lib and had no errors.

Thanks a lot.


I recompiled everything and the application is running fine except when I close the application I get this error:


Any ideas.


This error message means that the program executed the C-library free() procedure with incorrect parameter. Usually, call to free() is a result of some DISPOSE. Incorrect parameter can be an address of an improper variable (e.g. static) or an address of already DISPOSEd data, an address stored in the variable which has been erroneously overwritten, etc.

If you run into this problem:

  • find the PID of the running program, for example, using the Task Manager
  • find the TID of the thread which runs the error message box, for example, using WinSpy
  • attach the debugger to the program using its PID:

c60dbx -p pid

  • open the list of threads using Windows->Thread List menu item
  • highlight the row with the found TID and press Ctrl-Space key to suspend this thread
  • press the Space key to show the tread’s call stack in the Stack window.
1 Like

I will check that, but still I used all screens in the application and no trouble there. Why is it happening only in the application closing only.


Hi, sometimes the cause of the error is on previous code not the one that fails, could you post the prototype used for GetDiskFreeSpaceExA and other APIs, perhaps there is something wrong in there.


I am not using any APIs, when I got the first error I created a simple application which is one DLL application that have one simple procedure (stop message) and another EXE calling the procedure from the DLL. and all are working fine except when I close the application I get the GPF message.