If you are unable to withdraw your cryptocurrency balances from Kraken, there may be several reasons for this.
If you make any changes to your password, withdrawals to new withdrawal addresses will be held for up to 24 hours, for security purposes. Addresses that you already added to your account won’t be affected.
You may see a "Balance is insufficient for a withdrawal" error, or the withdrawal page may say that your funds are "Withheld" or that withdrawals are blocked.
Check the following:
Open or pending orders
Solution: cancel the open orders.
Open spot positions on margin
Solution: settle or otherwise close your open spot positions on margin.
Solution: deposit funds in the currency that has a negative balance or exchange other currencies to make up for the negative balance.
Currency not held in your account
An example is if you hold both Bitcoin (BTC) and Ethereum (ETH) in your account, you can't withdraw the total amount in one Litecoin (LTC) withdrawal.
Solution: exchange your balances to the currency you want to withdraw.