I would suggest you break off from what you are doing and train yourself on debugging.
You should expand the error messages at the bottom so you can see exactly what they refer to.
Why have you got Addfolder in there? AddExpandableRow takes a string as argument.
Click in the red circle with a white cross and read.
Not enough arguments: missing Folderitem value for parameter âfâ
This refer to some code not displayed on your screen shot.
When you will be on that code, move the MouseCursor above the offending line (where the error is), and read the help string near the window bottom / Read the syntax in the DocumentationâŚ
Not helpful. I have done that!
I was just trying to think of the right words, but Tim beat me to it. This is excellent advice.
You need to learn to work the problem at hand. The Xojo IDE is not perfect, but itâs pretty smart when it comes to errors.
Start with the top error message, and resolve just that one first. A bunch of errors may seem intimidating, but youâll be surprised by how fixing just one error can sometime resolve some of the others that you see (this is known as a cascading error). So your list of challenges can often dwindle quickly.
Your hint for the first step is right in the error message. Itâs complaining about arguments. So check the documentation for what AddExpandableRow requires.
So, does your call to AddFolder return anything? If so, is it the right âtypeâ of value? And so onâŚ
Hi Tim,
I canât quite break away from this task right now because I need to get it finished. However, I thought by what I have entered in the AddExpandableRow âItem.DisplayNameâ is a String.
Roger
Save your project (or a sample one) as binary, upload to the forum as zip.
Iâm sure someone will guide you on how to fix it.
Dear oh dear, it really is like getting blood out of a stone.
One of the important aspects of getting help here is to provide information when asked (if you wish to make progress, that is).
Never mind whether you found them helpful. WHAT DID THEY SAY?
Please answer my second question in my previous post.
No need to be rude. I am trying to learn as I go, but statements like yours are the kind that tend to move people away from learning.
I hate to break it to you, but we all have projects that need to get finished.
Yes, the forum is full of wonderfully helpful people, but they donât show up here on a schedule. Or when they do show up, they donât always have much time.
But that is not what you entered. Re-read that line of code.
You have (AddFolder Item.DisplayName) and not just âItem.DisplayNameâ
We donât know the code on your method AddFolder.
Yes!
Yes again.
Look, problems are not solved by hand waving or magic. They are solved by painstaking attention to detail and taking the time to learn. That is homework, and no one can do it for you.
Actually there are two errors and you only show the code relating to one of them.
Thatâs what I wrote in post 21. (f)
So you did! 
This forum must imagine it is Inspector Clouseau. Every time I go to post in this thread it says âThe case, it is solvèd.â