firstItem must be an iOSControl, iOSScreen, or a layout guide

Targets iOS
1

Getting the message in the title.

Here’s what’s strange: I was working on an older Mac (newer one was getting repaired), and things work absolutely fine. When new Mac came back, I moved the project back, and then I get this message. I have no idea what the message is about.

Running 2024.1.1 on both machines. (Newer one is M3; older is Intel.)

2

Hi @Bob_Gordon

Maybe something wrong messing with the cache? Have you tried to shutdown, wait ±5’ and start it again? Does it helps if you previously delete any already installed app in the Simulator having the same app name?

3

Javier,

Thanks for responding.

No joy.

Shut down. Waited. Same result. No other app in Simulator with same name.
Would it help to see the call stack?

4

Javier,

Currently there are three pages in the app. The first page is simply blank (added to help figure out this problem). Of the other two pages, one works and the other gives the message.

I think my next step is to rebuild the problem page a piece at a time.

5

Update.

I ripped out all the controls. The (now blank) page appears. I put things back one at a time. Still good. The last control was a ContainerControl. That caused the problem. Now this container control is actually a subclass of MobileContainer. Perhaps that’s the problem, but, again, it works fine on the Intel Mac.

More research is needed.

6

I may have found the problem:

The sub-classed container control has a Constructor. That seems to cause the problem. If I removed the Constructor, I don’t get the error. (What a fun way to spend the day.)

I will now put all the other methods back and see what happens.

Why this works on the Intel Mac and not this one is beyond me.

7

What does he Constructor do?

8

Final update:

The Constructor was the problem. I’ll leave it to the friendly Xojo people to find out why it worked on the Intel Mac and not the M3 Mac.

Hope people didn’t mind or did enjoy my adventure in debugging.

9

Apparently the mere fact of its existence is the issue. I commented out what it did at one point.

I wonder if the problem was that I didn’t call the super?

1 Like
10

Hi @Bob_Gordon

Would you mind to send over (privately if you want) the project so I can test it here? (or any other simplified project reproducing that behavior)