null reference error on closing dialog

[jded76]

I get this error (only on Internet Explorer and only on some rare occasions):

TypeError: Unable to get property 'focus' of undefined or null reference
at restoreFocus (http://localhost:9001/vendors~a3fd09b7.01e2e1f28a3ef0d6c8d3.chunk.js:866:60)
at DialogRenderer.prototype.detach (http://localhost:9001/vendors.async~253ae210.01e2e1f28a3ef0d6c8d3.chunk.js:1693:13)
at Anonymous function (http://localhost:9001/vendors.async~253ae210.01e2e1f28a3ef0d6c8d3.chunk.js:1778:33)
at Anonymous function (http://localhost:9001/vendors~f9ca8911.01e2e1f28a3ef0d6c8d3.chunk.js:300:7)

We can avoid this by changing this line :

dialog/src/dialog-settings.ts

Line 125 in 0c49b7d

public restoreFocus = (lastActiveElement: HTMLElement) => lastActiveElement.focus();

to :
public restoreFocus = (lastActiveElement: HTMLElement) => { if (lastActiveElement) { lastActiveElement.focus(); } }