there seems to be a problem with the "save password" function of the login window. 
each time i try to update the project i am prompted to type in my password in the login window. so far so good. i used the function "save password" before so it already shows my username and password. when i press okay it says access denied because of a wrong password. but when i manually type in my password the update works fine.
therefore i think there might be some bug related to the "save password" of the login window since other users reported the same behaviour.