Client crash using invalid translation key

1st Method - Server Only

You can create a book with the invalid translation which will crash a client upon opening the book

/give LX_Gaming writtenbook 1 0 {pages:["{\"text\":\"<3\"}","{\"translate\":\"translation.test.invalid\"}"],"author":"LX_Gaming","title":"Crash"}

2nd Method - Server Only

A server can craft and send a SPacketCombatEvent with the death message set as the translation key 'translation.test.invalid' (This key is present in the en_us.json file which is bundled with the client).

This packet will cause the client to display the DeathScreen, upon attempting to render the death message an exception will be thrown due the translation format being invalid.

3rd Method - Client (Requires Creative) & Server

A player can spawn in an item with the display name being a TranslationTextComponent with the key 'translation.test.invalid', Anywhere the name of the item is rendered will cause the client to crash.