For all those needing to upgrade, I downloaded 1.10.3 from:
https://nxtforum.org/nrs-releases/nrs-v1-10-3/... but I'm still having problems as indicated above. 1.10.2 doesn't recognise the new 1.10.3 client and says it cannot install any upgrade until after the blockchain is fully downloaded. That's not happening because the blockchain is still stuck on block 10000012.
What am I doing wrong?!!! Do I have to download the entire blockchain again? How do I do that? Do I have to delete everything - all the downloaded previous client files and delete the NXT folder containing the database etc. and start all over again with 1.10.3?
You don't have to delete the old files, but if upgrading doesn't work for you - delete them, delete everything related to Nxt and install 1.10.3 from scratch. You'll be able to use it instantly in the Roaming Client mode while blockchain downloads in the background.
Thanks freshman777. You're one of the few dependable people here. I couldn't download any further than block 10000012 no matter what I tried and I couldn't get to the red alert that enables an upgrade.
I uninstalled and deleted everything. Then I downloaded the SHA512 flavour of 1.10.3 for my 64-bit machine. After unzipping to my desktop all that popped out was a NXT folder with lots of files inside. The installer didn't pop out.
I clicked on the nxt Executable Jar File inside the folder and nothing happened. The same goes for the nxt application and other executables. I copied the NXT Wallet Internet shortcut onto the desktop, clicked on it, and the 1.10.3 wallet opened up and started the blockchain download, running on a remote node. It also recognised my NXT balances.
I don't think that the wallet shortcut solution is what is supposed to happen. I don't have the two NXT blue icons I had before for the NXT wallet and the NXT desktop server - just the single Firefox shortcut. But thanks for throwing me a lifeline. Appreciated!