Please reproduce your issue (make it happen again), then find extfs_for_win .log file located in the program’s directory.
Please also attach volume dump file, as described here:
Please also specify the operating system (distribution) name, architecture (x64, x86, etc) and tools used to format the disk to ExtFS, and whether encryption and LVM is used or not.
Then send the created files and Terminal output to Support Team. Make sure to provide detailed step-by-step description of the issue you’re encountering.