my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_dir              => $_ENV::TempFilesDIR,
    csv_sep_char       => "~", # not "\\~"

    # You might want to add
    f_ext              => ".csv",
    csv_auto_diag      => 1,

    # And if you want NULL support
    csv_null           => 1,

    # And add these to see what is going wrong
    RaiseError         => 1,
    PrintError         => 1,
    ShowErrorStatement => 1,
    }) or die $DBI::errstr;