I'm using Gambas like normal then when closing/reviewing a page tab in the editor, Gambas will close without an error.
So tabs for Forms, Form classes and Classes etc…
I'm trying to work out if this is a "me and my machine" problem or there are other instances of this being observed.

I've tried this with different projects and observed the same result.

The outcome is not consistent. I can test this and close-and-open a number of tabs and nothing unusual happens.
Go back to work and anywhere between a few moments and an hour can pass without incident and then it will crash again when I interact with the tabs.

Using Gambas 3.19.2 and this appears to only happen since the last update. This may be coincidental so testing the waters for anyone else who currently has this issue or has had it in the past.

Quincunxian said

Using Gambas 3.19.2 and this appears to only happen since the last update. This may be coincidental so testing the waters for anyone else who currently has this issue or has had it in the past.

Gambas 3.19.3 is on the market. Try it, to see if it solves your problem.

 For a some time I had gambas just closing on random occasions for no apparent reason during use.

But not had it for a while now.

 @GB : Yeah has not happened since last update so by accident or design, it now appears to be fixed.

@Bruce : Thanks for the confirmation - I get the feeling sometimes, that the errors I get are unique as nobody else seems to be reporting them.