Message XCOMM0219E INVALID LRECL/BLKSIZE FOR XCOMREST S/B 2020 RECFM=F may be encountered with TYPE=EXECUTE transfers.
Message XCOMM0219E INVALID LRECL/BLKSIZE FOR XCOMREST S/B 2020 RECFM=F indicates that the XCOMREST dataset being used for your TYPE=EXECUTE is from an older version of XCOM.
With XCOM r11.6 for z/OS, the LRECL and BLKSIZE of the XCOMREST(restart) dataset was increased to 3030. This will require that the XCOMREST dataset be redefined for use with XCOM r11.6 and 12.0.
You will find sample JCL to redefine the XCOMREST and XCOMGLOB in member DEFQSAM in our CBXGJCL library.