why does google chrome wont let me install extensions manually?

Question

why does google chrome let me install extensions manually?
im trying to install "getflash.crx" file when im open install it chrome kept on telling that "app,extensions, and user scripts cannot be added from this website'.i used to have this flashget extensions i didnt had any problem from before when i was installing it when all of a sudden my google chrome crash and when i open it,it suddenly sets its self on its default settings

Answer 1

If you really want to take the risk (to your computers' security), you can install unapproved extensions by opening the Extensions page (go to Tools then Extensions) then drag the .crx file from e.g. a folder on your computer to the extensions page.

Answer 2

Getflash Chrome

Answer 3

I wish to ask the same question as the previous person.