Lastpass has been my choice of password-manager for years and it has never failed to deliver. Recently, after updating to Firefox 37.02 the Lastpass addon started showing error as below. Clicking the `Ignore` button made the error go away with no consequences to the functionality of the utility, however this was annoying and I got it fixed by upgrading to a new PRE-BUILD of the Firefox as shared ahead.

"Assertion failed!
Program: ...com\platform\WINNIT_x86-msvc\components\lpxpcom.dll
File: e:\cygwin64\home\joe\crypto++\secblock.h
Line: 197
Expression: m_allocated
(for info on how your program caused an assertion failure, see documentation, etc)"


Luckily the solution was simply to get the latest addon version from - https://lastpass.com/lppre.xpi, as per the posting their community forum "this was likely a consequence of a recent compiler upgrade."