Disabling in Test Pilot didn't disable it.

[potch]

Seeing this in the Browser Console:

No chrome package registered for chrome://tabcenter/content/vertical-tabbrowser.xml
TypeError: function onxbloverflow(event) {

        if (event.detail == (this._verticalTabs ? 1 : 0))
          return; // Ignore other-direction events
        var tabs = document.getBindingParent(this);
        var numberOfTabs = tabs.tabbrowser.visibleTabs.length;
        if (numberOfTabs == 1)
          return;

        tabs._handleTabSelect(false);

} is not a function

DevEdition 48, a few extensions. Disabling Tab Center has worked in the past.

[bwinton]

Huh, can you reproduce it, and if so do you have a list of steps to reproduce? (I've heard about something similar from Matt_G, and wonder if this is related…)

[johngruen]

@potch bump

[ghost]

We haven't reproduced this, but suspect #226 may fix it