$ cat xmlh.awk

BEGIN { RS="<";         FS=">";
        # Uncomment to make windows-readable text files
        # ORS="\r\n";

        # Change this to alter how many close-tags in a row are needed
        # before a row of data is printed.
        if(!DEP) DEP=1
        SEP="\t"
        }

# Skip weird XML specification lines or blank records
/^\?/ || /^$/   {       next    }

# Handle close tags
/^[/]/  {
        N=D;    while((N>0) && ("/"STACK[N] != $1))     N--;

        if("/"STACK[N] == $1)   D=(N-1);
        POP++;

        if(POP == DEP)
        {
                if(!HEADER++)
                {
                        split(ARG[1], Z, SUBSEP);
                        printf("%s %s", Z[2], Z[3]);
                        for(N=2; N<=ARG_; N++)
                        {
                                split(ARG[N], Z, SUBSEP);
                                printf("%s%s %s", SEP, Z[2], Z[3]);
                        }

                        printf("\n");
                }

                printf("%s", DATA[ARG[1]]);
                for(N=2; N<=ARG_; N++)
                        printf("%s%s", SEP, DATA[ARG[N]]);
                printf("\n");
        }
        next
}

# Handle open tags
{
        gsub(/^[ \r\n\t]*/, "", $2);    # Whitespace isn't data
        gsub(/[ \r\n\t]*$/, "", $2);
        sub(/\/$/, "", $(NF-1));

        # Reset parameters
        POP=0;

        M=split($1, A, " ");
        STACK[++D]=A[1];

        if((!MAX) || (D>MAX)) MAX=D;    # Save max depth

        # Handle parameters
        Q=split(A[2], B, " ");
        for(N=1; N<=Q; N++)
        {
                split(B[N], C, "=");
                gsub(/['"]/,"", C[2]);

                I=D SUBSEP STACK[D] SUBSEP C[1];
                if(!SEEN[I]++)
                        ARG[++ARG_]=I;

                DATA[I]=C[2];
        }

        if($2)
        {
                I=D SUBSEP STACK[D] SUBSEP "CDATA";
                if(!SEEN[I]++)
                        ARG[++ARG_]=I;

                DATA[I]=$2;
        }
}

$ awk -f xmlh.awk DEP=2 data3.xml

SeqNo CDATA     redcode CDATA   GenError CDATA
43156489079     SKNEQGGEVHW     Upload-Success
43156489079     SKNEQGGEVHW     Upload-Success

$