I use a password manager to manage passwords on the internet. My typical password is 30 characters long and contains a mix of symbols, letters, and numbers.
I had to work hard to figure out what your password recipe was. I ended up using a 20 character password with a mix of symbols and letters after much trial and error.
Please update the form validation and messaging on your activation form with instructive messaging. Tell people what your recipe is.
Also, as a bit of advice, why restrict the length of the password? Set a minimum of course but not the maximum. Or set it higher than 20. In any case tell people what it is so that people like myself who use a password manager and follow best practices by setting unique passwords for every internet login they have aren't forced into a trial and error guessing session.
Here is the validation message from your forum which isn't very helpful. The activation screen was even less helpful in this regard.
