Re: Formula assistance

jaolvera I misread your question and now see that you want info on the missing IDs. My initial formula took ID's that were not missing. Then you should also check that e.g. the Last Name is not empty, otherwise the formula will result in a spill error. And I indeed forgot to properly format the Birth Date in the TEXTJOIN function. Inspired by flexyourdata , change the formula in S12 as mentioned below and it shall work in your Dashboard.

=LET(
    missing, FILTER(
        Linelist!B:D,
        (Linelist!B:B <> "") *
        (Linelist!AU:AU = "")
    ),
    TEXTJOIN(
        ", ",
        ,
        DROP(missing, , -1),
        TEXT(TAKE(missing, , -1), "mm/dd/yyyy")
    )
)