Created an attachment (id=7857) [details]
The error message

Initial installation of add-on was unable to create any filters, regardless of
the method attempted. Every attempt created message as shown in attached screen
shot.

Problem turned out to be caused by an over-aggressive sanity test which
triggers the exception if any account in the system has an empty email address.
I found one account (unused leftover from initial learning curve for TBird) in
this condition.

Removing that account entirely solved the problem.

Just to clarify in your case the application shows an error message:

"Exception in quickFilters.Worker.createFiler: idMail is null"

this is caused by an invalid account or account that has no from email address
and no reply to address. I will post a bugfix shortly.

Created an attachment (id=7858) [details]
qF 2.6 prerelease 55

This version guards against this problem and ignores the invalid account(s).
please mark the bug as fixed when it works for you.

Created an attachment (id=7873) [details]
qF 2.6 prerelease 60

This version adds replacement strings fore all missing strings for locales
other than English and German, replaces pre55.

*** Bug 25785 has been marked as a duplicate of this bug. ***