iMessage freeze and crash
After many attempts trying to fix this glitch I have finally found the answer.
I will explain step by step.


Open up iMessage
Quickly go back to the list of conversations before iMessage freezes
Go into the conversation that causes the crash
Click edit
Clear all messages
Go back before iMessage freezes
Delete the conversation
Completely close iMessage by opening up the Multitask bar and hold onto the icon until the icon jiggles.
Tap on the delete button on the top left of the icon
Wait 10 seconds then open iMessage again


After these 10 steps iMessage should be working find now.