When a file is uploaded into JCR, the standard file structure is:

• a node of type "nt:file" named with the name of the file (e.g., "MyFile.txt")
• a child of the "nt:file" node, named "jcr:content", where the binary content of the file is stored as property "jcr:data"

When the "jcr:data" property value is saved, the sequencing service detects this and attempts to sequence the "jcr:content" node. And prior to sequencing, the service attempts to detect the MIME type of the file content (using a combination of the filename and content, as configured). However, the service is grabbing and using the local name of the "jcr:content" node (e.g., "content") for MIME type detection, which is invalid. The sequencing service should detect this pattern and grab/use the local name of the parent of the sequenced node.

See the referenced forum for a suggested fix, although the fix should probably use the JcrLexicon.CONTENT Name constant rather than a magic string.