First ... backup what you have: moodledata directory and get a SQL dump of the Moodle DB.
One can upgrade to a 2.4 from 2.3 ... unfortunately, not from 2.2.x. Image may be NSFW.
Clik here to view.
"Copied and replaced the mod directory and config.php files from my moodle22 directory"
This is probably caused the issue related to plugins check.
The only file needed from the old moodle directory is the config.php file. The mods contained in the old 2.2 directory are not compat (versions) with code that you have.
What I would suggest:
Let's say your current 2.2.x Moodle is in a moodle folder
"git" a copy of Moodle 2.2.x stable in a moodlegit folder. This folder is at the same level of your file structure as the moodle directory.
git clone git://git.moodle.org/moodle.git moodlegit
cd moodlegit
git branch -a
git branch --track MOODLE_22_STABLE origin/MOODLE_22_STABLE
git checkout MOODLE_22_STABLE
Make sure your config.php file from the moodle folder is copied to the moodlegit folder. Did you have any add-ons (mods/blocks)? cp those folders into moodlegit. Let's say you had an add-on mod called journal.
While in the 'moodle/mod/' directory (which is your old code directory):
cp -rp journal ../../moodlegit/mod/
This copies the journal folder + files contained therein (r = recursive and p = preserve ownerships/permissions) to the mod folder of the newly acquired moodle code in moodlegit.
Then, rename 'moodle' to 'moodle.back' and rename 'moodlegit' to 'moodle'.
change ownerships/permissions on the new code in the moodle folder:
from moodle directory: chown apache:apache * -R
Now hit the site with a browser. That should throw you into a minor ... in a 'point' version ... upgrade.
Check things out. Every thing OK? You should now be at the highest version of 2.2. Backup everything you got!
Now we go from 2.2 to 2.3
from the moodle directory now (which is the recently updated 2.2.x code):
git pull
git branch --track MOODLE_23_STABLE origin/MOODLE_23_STABLE
git checkout MOODLE_23_STABLE
To see if the code is at 2.3, check the version.php file:
fgrep release version.php while in the moodle code directory.
Make sure all files/folders belong to apache user/group:
chown apache:apache * -R (you've not mentioned your operating system or some other details so adjust accordingly)
Hit the site with a browser. Login/Site Admin Notifications if it doesn't automatcially throw you into an upgrade process.
Ok, if that's successful and after you've check things out, BACKUP again, then we repeat the last steps taking your site to 2.4 from 2.3
From the moodle directory:
git pull
git branch --track MOODLE_24_STABLE origin/MOODLE_24_STABLE
git checkout MOODLE_24_STABLE
Change ownerships/permissions: chown apache:apache * -R
Now hit site with browser ... hopefully this will be the last upgrade process for a while! ;)
'spirit of sharing', Ken