Windows 10 Spring (2018) Creators Update

teddytoot - Yes, Microsoft have tightened up the security for downloads and pop-ups in their Edge browser.
Suggest go to the browser Settings hamburger and change the defaults for pop-ups and downloads - but ONLY if you are going to known, safe URLs for your downloads.
Also, I'd suggest use the Alt-tab key combo to expose any hidden dialogs that may be holding up your proposed download with a warning dialog.
Thanks but that didn't work. I solved it by resetting Edge. Obviously the update had corrupted it somehow. I did have a mild panic afterwards as it said it preserved favourites but I found it empty, eventually finding them as a HTML file in my Users folder.
To be honest, I was afraid that Google Chrome wouldn't work properly (and consequently Google Maps), but once the update was installed, I didn't notice any issues, although switching from Chrome to Trainz takes a little bit more time, as it appears a black screen for a few seconds. After that, the scenery appears. But beyond that, is working better than expected.