I installed Moodle, verion 2.6.3 some months ago on one server. I moved servers, but did not move the database (MySQL) and installed Moodle 2.0 on the new server and, of course it complained that the data files were incompatible with the Moodle version. After some difficulty, I got Moodle 2.0 to upgrade to 2.2, and 2.2 to upgrade to 2.6.3. Moodle runs, and obviously sees the database, but the moment I try to login, it sends me a message that "ERROR!!! The code you are using is OLDER than the version that made these databases!"
I pondered, and tried to install Moodle 2.7. I renamed the moodle directory to moodle-old tried softaculous installer, and it did not work. I cleared out all the code and downloaded a fresh copy of Moodle 2.7, unpacked it, and FTP'd it up to the server, checking paths and placements along the way. that did not work. I do not have root access to this server, and consulted the hosting provider who suggested reinstalling 2.6.3. We can see by the trail that the database was created under 2.6.3, and we reinstalled with softaculous, with the same result as above. I removed that install, and reinstalled from a .tgz file for 2.6.3 picking the weekly build. Again, I get the error message that the code is older than the version that made the databases. I can't imagine anything newer than 2.6.3 weekly build, except 2.7, and I can't get that installed. Since 2.7 doesn't seem to be an option, how can I get the database to allow 2.6.3 to work with it.
For what is it worth, I am using MySQL ver. 5.5.36-log, and PHP 5.5 and Apache 2.2.24.