When you can't view backed-up contacts and only seeing a VCF file/format with a white screen: (this why we may request a screenshot when you are trying to view those contacts but cannot OPEN the file, or ask cx what is displaying when trying to open the file.)
As per investigating, some Samsung/Android Phones' Contacts are being set/saved directly into VCard/V-File Format and this can be found in your Phone Contact Setting. A VCF file usually contains information such as the contact’s name and the media type for VCF file format is text/vcard. The Clickfree App can't read VCF format for now. For you to view it when using the Clickfree App, you need to change/convert first the Vcard contacts to NORMAL CONTACTS, and from there, you can backup again your contacts so you can view your contacts into your Clickfree USB device using the App.
Here's the step-by-step guide on how to convert VCard/VCF to normal contacts.
On your Android phone or tablet, open the Contacts app. At the bottom, tap Fix & manage Import from file. If you have multiple accounts on your device, pick the account where you want to save the contacts. Find and select the VCard/VCF file to import.
Or here's a tutorial link for you to check:
Here's the step-by-step guide on how to view VCF contacts using WINDOWS COMPUTER
TO VIEW VCF FILE, INSERT THE CLICKFREE INTO YOUR WINDOWS COMPUTER.
OPEN FILE EXPLORER>THIS PC>CLICKFREE (D:)>CONTACTS BACKUP>(Right click VCF file)>OPEN WITH>NOTEPAD
FN:Bege - Represents as Contact name
TEL;TYPE=CELL;TYPE=PREF:+639360536088 - Respresents as Contact number