Hi there,
first of all:
I'm happy that I found this forum, since I switched my private PC from Windows to Linux - not only for standard applications like office tasks (e.g. writing letters & eMails, browse the web etc.) but also for... doing some music recording! 
So I hope to get some valuable infos & interesting conversations/chats here. 
Anyway, but unfortunately even the registration was a small hurdle.
In the registration form, I entered all necessary information, including the password and its necessary repetition, got the confirmation email, confirmed the link and war informed that all's fine now and I could log in now - but that wasn't true...
Everytime I tried to log in, I was told I used a wrong password. But that wasn't possible, since I used copy/paste for that (by the way, as well as entering it manually).
I quickly had the idea that I might have used special characters for my password that were not permitted, as they (= my passwords) almost always consist of upper and lower case letters, numbers and special characters.
So I requested an automated pw reset and changed my pw to a much simpler one without any special character, and voilà: It worked well!
So in the end, the question remains:
Which characters are allowed for generating a valid password?
It would be great to have some information about all password requirements on every webpage where to set or change it. 