Forgotten quotes at line 1207 of functions.inc.php (pacrypt function) lead postfixadmin to die and display the "$CONF[encrypt] = dovecot:md5-crypt will not work because dovecotpw generates a random salt each time. Please use \$CONF[encrypt] = md5crypt instead." message.
Also, shouldn't there be quotes surrounding the "encrypt" in that message ?
Fixed file attached.