Is there a new "scam" and/or stolen wallet .zip file doing the rounds or something? 
Two different users... same wallet... same problem.
I tried to import a dumpfile from a local bitcoin instance to another new local "virgin" instance. Got an error message:
Command:
importwallet "C:\DumpedWallets\UsersAdministratorDesktopWalletsDesktopDBitcoinBUwallet.dat"
Response:
Importing wallets is disabled when blocks are pruned (code -4)
Command:
importwallet "C:\DumpedWallets\UsersAdministratorDesktopWalletsDesktopDBitcoinBUwallet.dat"
Response:
Importing wallets is disabled when blocks are pruned (code -4)
Tried:
14:39:37
importwallet "C:\Users\Ingvar\Desktop\WalletsDesktop\DumpedWallets\UsersAdministratorDesktopWalletsDesktopDBitcoinBUwallet.dat"
Resonse:
Importing wallets is disabled when blocks are pruned (code -4)
14:39:37
importwallet "C:\Users\Ingvar\Desktop\WalletsDesktop\DumpedWallets\UsersAdministratorDesktopWalletsDesktopDBitcoinBUwallet.dat"
Resonse:
Importing wallets is disabled when blocks are pruned (code -4)
Two different users... same wallet... same problem.