Hi,

It seems that one of these constants is wrong (either TS_MIME_LEN_CONTENT_ENCODING is 15 instead of 16 or TS_MIME_FIELD_CONTENT_ENCODING is "Content-Encodin" rather than "Content-Encoding".
This is since using both, when generating MIME header will result in a Content-Encodin rather than Content-Encoding

Best,
Moshe