The latest update of Thunderbird changed the column headings I've been used to seeing for years, without asking me. Now I've had to spend time fixing the results your inconsiderate treatment and then had to find my way here through all the stupid FAQ diversions. In the future, please ask before making changes that directly impact the visual and operability experience of this product. And why are you screwing with the mail client, when you need to be improving the interoperability of the calendar? I won't come back here again. I will change to another application if this treatment persists, and advise my clients to do the same.