Upgrading SQL and PHP
The oldest version of Concrete5 I have on the server is 18.104.22.168.
I f i have them upgrade MySQL and PHP, will I have a problem? Also, should I upgrade PHP to 5.5.15?
As far as PHP goes we are successfully running Concrete5 under PHP 5.5.15 and no issues. The only slight concern might be any additional add-ons that you might be running not supporting these, but so far I haven't run across any issues.
We've migrated several sites up from PHP 5.3 to 5.5 and MySQL 5.1 to 5.5 with no issues. Moving up to MySQL 5.6 is where occasionally you need to reset your database user passwords, but is usually not a big deal.