If you get "File mismatch", "inconsistent dat file" or other issues during update of NavStick from the NavBox please do the following:
Check separate helpdesk article Format 64GB NavStick as FAT32 if you have a 64GB NavStick and your ECDIS required the FAT32 filesystem.
Please perform the following to restore the NavStick
1. Right-click on NavStick in "My Computer" and format the NavStick with the options shown in the attached screenshot
(use FAT32 for Furuno FMD/FCR 3xxx, SAM ChartPilot, Danelec G2, Simrad E5024, Olex, SEAiq Pilot, ECPINS V.6.2.1, Raven INS, RYECDIS-2012L - all others use NTFS)
2. Copy all files and folders from the NavBox PC in C:\Navtor\ENC\AVCS\ or C:\Navtor\ENC\NAVTOR (depending of database you have) to the newly formatted NavStick
This should ensure that the NavBox and NavStick are identical.