I haven't seen anyone else mention this, but I had some problems getting 1809 to install correctly. I wasn't watching it too closely, but believe my Lenovo Yoga 2 laptop cycled through initializing, downloading and installing at least a couple of time before prompting me for a restart. My big desktop upgraded with any issues. However, I couldn't get it to install on my wife's desktop (HP); it would go through the upgrade sequence after restarting but would apparently end up reverting back to the previous build. The Windows upgrade log showed that it had failed. I did this twice before finding that the update was unceremoniously withdrawn. Thankfully, I had no obvious file losses.