How to resolve the "Unknown Key" error presented in File Share Encryption?

Hi,

I encrypted a file using the Symantec Encryption Desktop - File Share Encryption and by mistake a deleted the key that is assigned to an encrypted file that I'm using for tests.. Now, if I go to "File Share Encryption" I can't remove it the file from there.. it says the message that is presented below in the image:

If I don't have the key how can I remove this folder or re-assign a new key to it?

Thanks,

Carlos