Seems the 1903 upgrade issues have begun:
bharris
<p>I had a similar issue upgrading to 1809. I guessed that it might of been an accessory so I unplugged all USB devices but the keyboard and it then installed fine. I assumed that it was an USB driver issue but evidently it was just that I have some USB drives.</p><p><br></p><p>I'm in no hurry for 1903. Running Pro, I plan on delaying taking it for at least a month & more if problems start emerging.</p>