Aloha! I wanted share this with everyone (and for future me when if I forget). I oddly couldn't login with 'admin' after recently installing another dev instance of C5 (5.6.3.1) under MAMP. After learning that 5.6.3.1 no longer saves the salt in config/site.php (which is likely more secure), I was stumped when I couldn't login - UNTIL I REMEMBERED, I installed C5 with version 5.5.3 of PHP but I had since switch the PHP version to 5.2.17. Interestingly this causes the password checking code in PasswordHash.php to no longer work. After switching back, I can login again!

Lesson learned: Do not switch PHP version after an install!

Ciao,

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