The "Import" command gives the same error message:
"Importing wallets is disabled when blocks are pruned (code -4)"
Stuck!!
Anyone has an idea how to get around this. The dumpfile is what I have
(I know. I should have taken a backup of the wallet before creating the dumpfile)
The error is regarding the state that your client is in. With the pruning enabled, the client actively deletes information that are irrelevant to your old wallet and the older blockchain files. With that, if you import an entirely new wallet, there is no way for the wallet to get all the transactions that are in your wallet currently.
You'll have to synchronize your wallet again, without pruning if you want to swap out your wallet files regularly.