Running Xojo 2018r4.
I tested a new bare Web project with App.Open having a single line of code:
Raise New RuntimeException
If I build that project with no App.UnhandledException event handler, and then run it on a server, it loads WebPage1 and no error file is produced.
I then added the App.UnhandledException event handler with a single line of code:
Building that second project has the same results.
I was doing this to see what the user would see during an App Runtime Exception. Shouldn't the the user see the default dialog that asks for input, with an errors.log file being created or appended?