Are you talking about when it crashes like it exits and it doesn't display an error message? I've been trying to reproduce those to report them but it's difficult to get an accurate test but this happens commonly if you close a debugger preview after you made some changes to the code while it is opened.
And for anyone that doesn't know how to use worker mode just do this:
1) Select your project folder
2) Click on "view properties"
3) You'll find it under the "ADVANCED" section >> "Use worker" tick box.