1. What is the problem? Be very detailed.
After pulling the data (pulling successful), I try to export the data and the ODK Briefcase hang on "Starting to export form" and nothing happens.
2. What app or server are you using and on what device and operating system? Include version numbers.
ODK Briefcase v1.16.2 on Windows 10.
3. What you have you tried to fix the problem?
Delete the ODK Briefcase Storage folder, Change the directory, pull again and again 
I Tried with version v1.16.1 and the export works perfectly.
I Shared privately the ODK Storage directory and the log file with @ggalmazor.