I would start by commenting out the call to EditButton() and see if that fixes the error.
If that doesn't work, comment out the code to create the "hi" toolbar item.
The only other thing I see that could cause a problem is the following line of code:
Text("Item at \(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard))")
That string looks fishy. It looks like you're missing a parenthesis at the end of item.timeStamp. I would start with something like the following:
Text("Item at \(item.timestamp)")
And add the format argument to the item text after you get the basic text to appear in the list.
Topic:
UI Frameworks
SubTopic:
SwiftUI
Tags: