Hi,
This latest update got into a loop of failure and the following solved the problem for me:
If the update fails, then go to:
PortableApps\ThunderbirdPortable\App\thunderbird
rename:
mozMapi32.dll to something like mozMapi32_old.dll
Then click ok in the loop that keeps failing in the update.
This time it will complete but say: "partial update, going to get a complete one" or something similar, then that update will install and run fine.
Hope this helps,
Hfuhruhurr
you know that until Mozilla fixes this bug, you should not use the built-in auto update!
"What about Love?" - "Overrated. Biochemically no different than eating large quantities of chocolate." - Al Pacino in The Devils Advocate