Global Mapper v25.0

GM_ExportWebFormat() hangs

oic_chris Global Mapper User
SDK v18.2.1 32-bit
Visual Studio 2013
Windows 10


The function GM_ExportWebFormat() hangs when attempting to export Web Tiles (OpenStreetMap).  Please see the attached test VS2013 project.  Upon executing GM_ExportWebFormat(), a progress dialog pops up and does not change from 0%.  After a short moment, you can no longer interact with it and Windows marks the application as "Not Responding".  In a previous version of the SDK (v14.2), the export proceeds successfully.

On a side note, if the line with the GM_ExportWebFormat() call is commented and the project is run from the VS2013 debugger, an unhandled exception occurs.  This happens upon exiting the main() function and trace places the it in a function call within the GM DLL with the following error:

Unhandled exception at 0x7793507C (ntdll.dll) in gm_export_hang.exe: 0xC000000D: An invalid parameter was passed to a service or function.

This does not occur if the application is run from commandline or launched from Windows Explorer.

Much mahalo!


  • aaronc
    aaronc Trusted User

    I'm looking into the error you are having.  In the meantime we just fixed a similar issue in 18.2 so you might try our latest build found here:
  • oic_chris
    oic_chris Global Mapper User
    Aloha aaronc,

    Much mahalo for your response and the build.  Unfortunately, both the hang and the exit crash also occurs in the latest build (b36).

  • aaronc
    aaronc Trusted User
    Answer ✓
    We haven't figured out what is causing this in 18.2 but it is fixed in version 19 which is now available on our website:

    If you want to try using version 19 to make sure that it does in fact work for you. Just send a request for an eval license to
  • oic_chris
    oic_chris Global Mapper User
    Aloha Aaron!

    After playing with the issue a bit more, I believe I localized the issue and found a workaround.  I think there is an issue with the WinGDI/UI code, because when I set a callback via GM_SetProgressCallback(), the progress dialog doesn't show and the export proceeds normally.

    Much mahalo for your time and support in looking into the issue!!

    P.S.  If the above gives you insight to a quick and simple fix, please let me know.  We won't be able to upgrade to v19 for a while.