/blockdata ~ ~-1 ~ {Text1:"{text:\"Test\",bold:\"true\",color:black,clickEvent:{action:\"run_command\",value:\"/tellraw @a

\"}}",Text2:" ",Text3:" ",Text4:" "}

on a sign crashes the game.... I did not write or run this command and it seems to only happen with a specific sign in my world so I have no idea how to repoduce it yet other than cloning the bugged sign