Game crashes when command in command block is too long

Well, I'm creating some only one command command block vanilla mods.
Sometimes I reach the character cap in a command block.

However, for some reasons I can enter more characters than minecraft can process and when I try to press the done-button the game crashes.

At the beginning of my crash report there's written "io.netty.handler.codec.EncoderException: String too big (was 32764 bytes encoded, max 32767)"

You'll find my crash report and the command I tried to enter ("CommandIsTooLong.txt") in the attachments.