Transactions and balance issues
1. On a Mac OS computer your need to uninstall and reinstall the Ripple wallet. On a Windows computer you need to press Ctrl+Shift+A to reset the data. After cleaning, the next synchronization will recover all your transactions.
2. Click on "Change Node" and replace s2.ripple.com by s1.ripple.com
Transaction from an exchange with message "invalid address"
Some exchanges cannot send transactions to an empty address (the address must be "activated" which means that it must have a minimum of 20 XRP). In that case you need to receive 20 XRP from another source or exchange.
If the Ledger XRP Wallet displays "Unable to synchronize your wallet" it may be a program on your computer that interferes and prevents your Ledger device to work correctly. It could be an application like Mist, Geth or Parity, Electrum, Bitcoin Core...
Please close all the other programs that run at the same time as your Ledger device, disconnect and reconnect it, and/or try to use your Ledger device on another computer.