Have you been using a Trial Version of SE 4 and have the license expire, once purchased the core, plus blogs, forums, and photo albums modules. You need to started with the upgrade instructions, by copying files over into the existing directory structure, but you may not proceed, as any time you hit the site, You may have received the “License expired” warning. I assume this is because you have some modules enabled that you hadn’t purchased. If you try deleting the license.txt file, clearing the cache (see below), and a few other things, but got nowhere.
You need to copy the new core to a different directory, copy over from the OLD directory structure, in application/settings the following files: database.php, general.php, mail.php.
Then clear the cache, instructions here:
Then go into the db using phpMyAdmin, find the table ‘engine4_core_modules’, and disabled all modules with a type=’extra’.
Go into ‘engine4_core_settings’, found the ‘core.license.key’ entry, and updated that with the new license key.
You can now log into my site, do the upgrades, and install the three purchased modules. May need to re-upload some heading images, you may have temporarily lost some template changes you had made, but nothing major.
There you go you now should have a fully licensed version of SE
Hope this helps someone.