Hi,
The “Your MySQL settings are incorrect, do you wish to run kaltura-mysql-settings.sh in order to correct them?” should be answered with a YES, or else, you can manually correct it yourself if you'd like.
You can see exactly what the script will do, simply open /opt/kaltura/bin/kaltura-mysql-settings.sh in a viewer/editor to see.
As far as your problem to login goes, you need to SSH to the server and:
# . /etc/profile.d/kaltura-base.sh
note that there is a space between the '.' and /etc/profile.d/kaltura-base.sh. This means sourcing the ENV vars of /etc/profile.d/kaltura-base.sh into the shell, when using BASH, you can use the 'source' command also.
then run:
# kaltlog
and try to login in the web I/F, it will output errors to STDOUT and STDERR, check what they are and go to the log at /opt/kaltura/log/kaltura_api_v3.log and /opt/kaltura/log/kaltura_apache_errors.log to check what leads to the final error.
One option is of course that either MySQL or Sphinx are down but there can be many other reasons.