Hi,
FIRST: Do not do what you are doing, please, please, please, please DO NOT. And now I will answer you.
You are not going to always get nice specific errors.
Firstly, an error that YOU catch in the Flow, allows you to pass back the information (as long as you catch it IN the flow) to the caller, however you want.
However, when an error occurs that is outside the scope of the Flow, you get back what the Platform Decides.
My recommendation is to do this.
1. If you do NOT add an error handler into your code, you MUST add one in the OnError of the App. Its a property like OnAppStart
Any errors NOT caught, end up here, if you don't handle them here, it's the Pink Ugg of Doom Message that people get
So you would have to look up the error codes you think you will get, handle the ones YOU pass back into the OnStart,
For anything you cannot handle rethrow it to the OnError
And have codd there to do something with it.
LASTLY: DO NOT DO WHAT YOU ARE DOING
If you want to do what you are doing please change it to this.
1. Create a Full Form Blocking Window, that is opaque (just a square)
2. Add a Spinner (download one, buy one, build one, its all easy)
3. Group these two things together and make sure the Spinner is on top
4. In your OnVisible, FIRST make these 2 things Visible, with the spinner saying something like Please Wait XYZ
5. Then call your Flow
6. Do whatever you are going to do with the Error and App.