WD Easystore in now write protected

I have a 4 TB WD Easystore that was working perfectly until last week when I disconnected my computer for some routine and unrelated service. I plugged it back in and can see the directory just as it was on 12/31/208 when disconnected and Windows flags 2.8 TB of free space just as it should, but when the backup tries to run it goes through the full process, but then tells me “Backup failed, The media is write protected”. How do I remove the write protection. I checked online, but seemed to only find very long processes that seem unnecessary. FYI, I am using WIndows 10 and the drive is set-up for daily back-up??

Follow-up. This is not as simple as updating the drive in Disk Management. First off I was able to manually copy/paste a file from the internal hard drive to the Easystore, so that was not blocked by Write Protection issues. Then, checking in Disk Management the drive looks fully healthy and available. WHen I run backup it runs through the process building up the percentage complete, but fails to actually do the backup once the reading part of the process is complete. Anybody know what can happen when an external drive is disconnected (I admit I did not “safely” remove it) and then re-connected that can interfere with regularly scheduled backups?