Monika,
I did try, and guess what, it failed installation too! This time there was a little better explanation as to why it failed. It seems that during installation of version 1903 the installation tries to put any external drives, or flash drives you may have plugged into a USB port, or even an internal Hard Drives into an order: C, D, E etc.. and if they're not in order it may change them. It gives an example of maybe changing a flash card now showing as G:\ changing it to H:, and in order not to cause any conflicts, it aborts the installation (that makes sense). It says they are aware of the problem and will hold off sending the update to users until the problem is resolved by Microsoft. They did have a workaround, removing all external USB Hard Drives or Flash Cards, and trying installation again. I really can't do that because I have my external hard drives, and even my internal hard drives lettered to make sense to me, not necessarily in sequence. I have 2 internal hard drives that I use strictly for storing my home videos, and all family photos, V:\ Drive for Videos, and a P:\ Drive for my photos. External drives are set to backup those drives on a daily basis, so I would have to not only change my Drive lettering, but also redo my backup setup to agree with that change, too much work, so I'll wait for Microsoft patch. I wonder if all these cumulative for 1809 are attempting to do that?