Reply window doesn't load properly

Reply window doesn't load properly

Build 15150.

This only happens on a single conversation within a single ticket. I believe the root cause might be some dodgy html within the conversation reply.

The text box to type the reply doesn't properly load. This happens the same for other technicians to the same reply also, not just my account.

If I click reply on the previous conversations on the same ticket then it loads fine.

Perhaps if I could find this conversation in the SQL database then I can check/fix the html?