Signal 6 was raised (null)

This app from Apple Store it created from Thunkable.
You can download and check. (Some one buttons have same bug. Normally When some one button clicked webview .html page will be open.)

Yes, tap F.A.Q. and see (iOS 12.3.1)

So, Is it any solition?

What happens in the project when you click on this button? Perhaps, an error occurs while working with memory - an attempt to work with a non-existent object (an object for which no memory was allocated).

In the iOS development forums, ask the developers how to get this error log.

It is not good idea.
Normally it was working 3-4 days ago.
I added .html page after than now it happened. (Buttons click happen to open to webviev screen I will add photo what include code)
code

Can not say anything. I know that on Android there is a problem with displaying html pages. If you remove the html then everything works well? Did you check it in Live and on a test installation under iOS?

If i delete .html webview seeing whitescreen you can see what i am saying.

And also same bug. When i change code i mean i changed old ones.It is really strange

Any one know?

Did you find a fix I’m stuck on signal 6