On the other several accounts all looks fine except the Subject pane opens blank and a pale yellow background then over a second or so feeds in the Subject lines. Working fine after that.
A close and reopen of TB didn't solve it, nor did a warm reboot of the laptop.
I remembered something about a repair option in the menus but at the moment I haven't found it. What I have found in the Error Console is
Timestamp: 18/09/2015 14:34:57I have checked out the host server using Webmail and everything including this mornings receipts is still there.
Error: path is null
Source File: resource://gre/modules/osfile/ospath_win.jsm
Anybody got any instant solution please, before I start on a few hours of searching for it?