I was trying to send a PM but it seems to hang: after clicking the submit button this disappears and it does not happen anything else. With short messages it seems to work fine, but it appears slow.
When I try to submit a message with ~9k characters, I have no success and get this in the console log:
Failed to load resource: the server responded with a status of 500 (Internal Server Error)
Where the resourse is
I'm not sure this is due to the size of the message or to the code blocks.
By splitting the message I had success, so it seems to be the size.