4TB sandisk stopped working

i bought my 4TB some nine months ago and now keep telling me it is full i had to transfer some content to my laptop to ad my new content but still telling me i have no space is my external drive no use any more is there a salutation to the problem

Hi @martinashak

If you have any important data, we request you to back up the data and format the drive using the below mentioned link.

Title: Steps to Format a Drive for Use with Windows or macOS
Link:Steps to Format a Drive for Use with Windows or macOS

thank you very much i fixed the problem