*Developmental Build*
Mozilla has released Thunderbird 19 Beta 1 on January 18, 2013. Note: Developmental (Beta, Earlybird and Daily) builds will continue to follow the current Gecko version numbering. This release includes fixes and improvements to chat.
Lightning Users: Lightning version 2.1beta1 is needed for Thunderbird 19, however this version is not currently showing on the Development Channel section of the Lightning page at AMO.
Thunderbird 19 will be released as Thunderbird 17.0.3 (or the current Thunderbird ESR version) on February 19, 2013.
*Developmental Build*
Hacking the install.rdf won’t get Lightning 2.0b1 to work. It did work with 2.1a2. YMMV.
Hey, what ya know that worked! Just changed the max version from 19.0a2 to 20.0a2. For those who know what you are doing you can get 2.1a2 off of the FTP Server.
2.1b1 worked. https://ftp.mozilla.org/pub/mozilla.org/calendar/lightning/tinderbox-builds/comm-beta-win32/1357996868/
Perfect, updated.
Thanks so much for that info. 2.1b1 worked.