The safest way to acquire Global Mapper Pro is through the developer, .
Download the (.exe) rather than a .rar archive. Right-click the file and select Run as Administrator . Download GMPro Build 091421 x64 rar
Troubleshoot you might be seeing with the x64 version. Download Global Mapper - Blue Marble Geographics The safest way to acquire Global Mapper Pro
Suggest like QGIS that offer similar Pro features. Download GMPro Build 091421 x64 rar
If you are looking for a specific or having trouble with a license , I can help you: Find official documentation for that specific 2021 build.