The problem is likely your underscore. That's why I tell you to only use letters and numbers in your field names and your table names and such. Try putting brackets around it. And don't forget if that criteria is a string value, you need quotes as well.

"[LAST_NAME]=""" & LastNameField & """"

Is everything spelled correctly?
Since you are using an underscore in your names it is advisable to enclose them in square brackets.

Enter Parameter Value

Beat me to the punch Richard :)

It worked for a long time and then I migrated to a new DB cleaned up tables and Q renamed fields and eliminated redundant data, and now that the DB is clean and fresh it doesnt work....I hope you can help as I have spent hours trying to figure out what minor infraction I have created

Thanks let me get rid of the brand new underscores....and see that fixes it..

What Data Type is your ID field?

The reason I ask is you have declared passvalue as a String variable.
The ID is numeric so passvalue should be declared as a Long.

the value of the id is i121 ....the IDs begin with i (eye)

I have taken all of the underscores out...and still not working...

Kevin what is the easiest way to delete the first character "i" so that I can make my IDs numbers?

String Functions
Update Queries

Dg I have tons of underscores in table and control names (since Ver. 2018, now 365). Not yet any problem whenever I need them. No brackets needed. Probably some other problem, since it remained after removing "_".

I'm thinking if your Father_ID is a string, you'll have to surround it with quotes.

Thomas   Where would I put the quotes?

Private Sub FatherID_Click()
   Dim passvalue As String
   Dim strsearch As String
    
     passvalue = Me!FatherID
    
    DoCmd.Minimize
    
    MsgBox passvalue
    
  DoCmd.OpenForm "MDKA_Form", , , "INDIID=" & passvalue
  
End Sub

Double Double Quotes

my gut is telling me that it has something to do with getting the passvalue from a subform and trying to filter on the mainform...

Kevin  could you rewrite the code so I can see what you mean,  I have always struggled with double double even after watching Richard's video over 100+ times....

You have to include your pass value inside of double-double quotes. And I would still put the field name with the underscore inside of brackets. You don't need it everywhere, but sometimes you do.

DoCmd.OpenForm "[MDKA_Form]", , , "INDIID=""" & passvalue & """"

Being klutzy with typing, since I couldn't just copy & paste your code, it's best to let Richard, the speed typist, do it.
Which I see he did.

Did that solve the problem? I'm guessing that Access didn't like what you passed in, so it just popped up the box asking, "So, what do you want here" (Enter Parameter Value), instead of some appropriate error message.

Which highlights a better way to program when you call subroutines. Instead of letting the subroutine just try to handle an error, it's a good programming practice to pass back an error code to the calling routine and let the higher-level routine give a better error message or deal with it appropriately. In this case, it looks like the SQL routines for the passed parameter dealt with the error instead of DoCmd.OpenForm throwing a runtime error (which would have eliminated all your huh?).

Richard Yea, after determining I had too many "INDIID="""" & ....

It Works!!!!!!!!!!!!!!!!!!!!!!

I hate the double and double quotes.....I just don't get the logic (yet)

Watch this video too. It might turn the lightbulb on:

DDQ Not SQ

Richard The light bulb (with rheostat) started to brighten when you gave the origin of double double being a function of concatenation.....

and then when I looked at the what property value needed in the filter property, the rheostat went to full blast....I have the logic solidly nailed.....it will take some practice to get the syntax to be natural

Thanks, you are and have been the number 1 instructor of my 70+ years....and I have had some really awsome instructors!!

Dg awesome. Glad you figured it out - and thanks for the compliment. :)