i keep getting a message "We have released an update for the current client. You must redownload it here to play." some games i can play... but there are some that i can't...

Don't worry about it if you have already installed the newly updated client you should be good, and if so just ignore the message as it is happening to me to

This is because some server hosts have not updated their servers to the latest update
Your client is up to date but servers are outdated