[Affected versions]: Nightly 56.0a1 [Affected platforms]: Platforms: Windows 10 x 64, Mac OS X 10.12 and Ubuntu 16.04 x64. [Steps to reproduce]: 1. Open Firefox and go to https://devtools-html.github.io/debugger-examples/examples/todomvc/ 2. Open Debugger. 3. From "Watch Expressions" section click on "Add Watch Expression" and type the expression you'd like to watch into the text field (e.g el: this) and press "Enter". 4. Navigate to todo-view.js 5. Right click on the gutter, any line with written code, select add a breakpoint (e.g line 34) 6. Go back to todmvc and add a todo item in the UI and observe "initialize" function in Source pane. 7. Click on "resume" from the toolbar. [Expected result]: When you resume the watch expression should be removed. [Actual result]: When you resume the watch expression remains.

Tracking this here: https://github.com/devtools-html/debugger.html/issues/3461

This was fixed here: https://github.com/devtools-html/debugger.html/pull/3484 and should land in the next debugger update

This should now be resolved on nightly. https://bugzilla.mozilla.org/show_bug.cgi?id=1385421