2008 series Geo running TerraSync v5.9 will produce a TerraSyncWebServer.exe error. Unzip the attached cab file, copy to the Geo and run it from File Explorer. This should resolve the issue.
This was a bug in TerraSync version 5.8 where the software would crash when trying to save a feature while a data file was open as a background file. upgrading to 5.81 or later will fix the issue.
Visit the rental story map to get all the basics on collecting data, navigating, and transferring data using TerraSync and Pathfinder Office. https://storymaps.arcgis.com/stories/6400358a8a3b4fa99a350b119cd903f2