Many thanks for your reply.
After your reply, I've done step 1,2,3 as per your proposal.
Concerning step 4, there is no "mempool.dat" in "%APPDATA%/Bitcoin" directory (or subdirectories), so nothing to delete on my side

From step 5, I only closed "ArmoryQt.exe" only due to the following elements :
As per your "intuition", Bitcoin core node was not up to date, so I updated it (I would have imagined that I would have seen before an error message from Armory if the Bitcoin core node was too old).
Currently, Bitcoin core node is updating blocs for hours ...
Because my SSD 256Go (Windows drive C) will be full very soon, my questions are :
- Why do I need to update so many blocks (weeks), as my Armory wallet 0.96.2 was already updated ?
- Will Armory wallet update again for hours after Bitcoin core node blocks update ?
Armory requires a full, up to date, node (Bitcoin Core) to be running in order to use any networking functions.
If you do not have the disk space available for a full node, this may not be the wallet for you.
Armory will need to scan the new blocks, yes. How long depends on how out of date and your hardware specs.