T4 XML Issue is more than just the invalid tag name.  The 2 new tags empt_prov_cd and empr_dntl_ben_rpt_cd  are being generating in the wrong spot. They need to appear at the end of data block just before the T4_AMT block, instead they are appearing as the first two tags after the EMPE_ADDR block (before the SIN)  which is wrong and causing file rejections.  CRA is very sensitive to the position of the tags.  here is the official layout reference:  T4 Statement of Remuneration Paid - Canada.ca