Thanks in advance. Great email client. Something in recent Linux 18.04 update(s) has clobbered (client's) TB 24.6. Default account doesn't respond normally to selection by mouse -- entire program hangs and requires restart. No response from default account's Inbox, at all. Have deleted .msf files, but to no benefit. On TB restart, the initial page is completely blank, but fully functional. Where one "guesses" where the menu bar is or the accounts and associated folders, one can click on something and typically activate that initial screen. But, typical up/down arrow scrolling through the Inbox(es), Sent, etc., and Local Folders, hangs the entire app. Internet connection to the Add-ons page/menu is completely unusable -- no connection. Reinstall in the normal manner didn't produce any difference. TB 45.8 seems to be functioning normally. Working on a rebuild. The hope is that there's a system library that updated in the recent updates/upgrades beyond where 24.6 goes and that using the built-in libraries will solve these problems. The Linux box has Mercurial, mozilla-central (in ~/src/ mozilla), and comm-central (in ~/src/mozilla/comm). The box has 24.6.0 source code extracted and in a comm-central level folder (~/src/mozilla/comm-esr24). That build-from-scratch effort is as far as "autoconf2.13", "./configure mozconfig", and "make", but it hangs on the export recipe. (It "self-flxed" a "Circular CLOBBER" problem, but this one isn't self-fixing, at least not yet.) It's erring out in the section with nsinstall and the ultimate termination error is that a symlink can't be made because the/a file exists. Can't really tell, yet, which file exists or why there's a symlink. The error message is long enough that it just cuts off. What else can I get you in order to get another perspective on what's causing this build to fail?