Global Mapper v25.0

GM v17.0 (x64) writing 50+ GB of data to local C-drive


I recently had Global Mapper crash while trying to save, and my windows dialogue popped up saying I didn't have enough space on my C-drive. After doing a search, I saw under my user folder in the temporary files, there is a Global Mapper folder that had 50+ GB of files saved.

There are ~1,200 individual files all with .tmp extension. The names are all some variation of MAP####.tmp. All were modified at the time of my saving the Global Mapper file that crashed.

What are these files and why does GM need to create these? If it's a couple GB of data and I can run disk cleanup to remove them once in a while, it's OK. But in one day (or one instance in this case), it wrote 50+ GB! 

Any suggestions would be greatly appreciated.

Thank you,


  • PShorey
    PShorey Global Mapper Developer Moderator, Trusted User
    Answer ✓
    Hi Cindy,

    Global Mapper will sometimes create temporary files while loading and exporting data. During export to a package file for example, data for the individual layers is exported to temp files, then assembled into a package. Sometimes they do not get cleaned up, particularly if the load or export fails, and may accumulate over time. It is safe to delete them. In your case, you say they all had the same modification date/time which is interesting. If you could verify that GM creates and leaves 50 GB of temp files behind during a single export, we would like to look into this. Depending on what you are doing, this may not be the intended behavior. Please contact and describe the types of layers you are exporting and the format you are exporting to.
  • Thank you for responding. I've since contacted geohelp and they have released a new daily build to troubleshoot the issue.

    I can confirm that some (50%) of the temporary files disappear themselves after the workspace is finished saving and is closed. For the remaining files, I can safely delete them (manually) and it does not affect the workspace or associated files.