Little hard to reproduce but has come up several times. Selecting some text, playing around with the inspector and pasting some text.

Stack:

Uncaught TypeError: Cannot call method 'canHaveChildren' of null

ve.dm.Document.getNodeFromOffset
ve.ui.Toolbar.updateTools
ve.EventEmitter.emit
ve.dm.Surface.change
ve.ce.Surface.onPaste
jQuery.extend.proxy.proxy
jQuery.event.dispatch
jQuery.event.add.elemData.handle.eventHandle

ve.dm.Document.prototype.getNodeFromOffset = function(offset) {

var node = this.documentNode.getNodeFromOffset(offset);
if (!node.canHaveChildren

Uncaught TypeError: Cannot call method 'canHaveChildren' of null

()) {
    node = node.getParent();
}
r

Version: unspecified
Severity: normal