[cpt.zombies]

it says my ticket failed authorization what does this mean?

[Loxtonjoel]

Try re-connecting to the server again, if this doesn't work try restarting your Unturned. If both fail Re-boot your computer.

[RagnarosPower]

it says my ticket failed authorization what does this mean?

That means that your steam account has been made for less than 14 days so you need to play on it more till you reach 14 days on the account in order to join.

[cpt.zombies]

so I cant paly with my friend

[Mushy]

Have you tried http://pandahut.net/validate/ to verify the integrity of your game files?