encryption.xml of content protected epub about epubcheck HOT 2 CLOSED

I had same problem so, I changed the file as the below.

<encryption xmlns='urn:oasis:names:tc:opendocument:xmlns:container' 
xmlns:enc='http://www.w3.org/2001/04/xmlenc#'>
 <enc:EncryptedData>
  <enc:EncryptionMethod Algorithm='http://ns.adobe.com/pdf/enc#RC'/>
  <enc:CipherData>
   <enc:CipherReference URI='your font path'/>

However, I still had the error: 2. ERROR: /META-INF/encryption.xml(5): 
unfinished 
element
Do you solve the problem or fix the error?

I have made several fixes in this area. Adobe font mangling will continue to be 
flagged as a warning, IDPF mangling will not.