Kishore, have you made any changes to the database? as in upgrading it or changing permissions? or even changing PHP?
have you copied over the config.php file to new moodle 2.9 folder?
Kishore,
you'll find two folders in your "moodledata" folder
localcache
and
cache
Delete them both, and refresh browser, things will start working for you. and dont worry deleting them, as once you click reload/refresh, these two folders will automatically recreated for you.
This happens due to corrupted cache (so far I experienced this on window installations with Apache only), but I have given you a solution, lets see if this works, if it didn't then permissions need to be set correctly.
Barb,
The issue is clear, installing moodle from a script installer, and that is NOT recommended, for script installers do not keep up to date versions of moodle with them, but only base versions, like they will keep 2.9, but not updated versions like 2.9.x, so sometimes there are files missing or corrupted from package installer.
Best thing you would have done is, downloading the package from Moodle site and then upgrading even if your initial install was from script installer, all you have to do is copy over plug-in folders and config.php file to new moodle folder.
Kishore, have you managed to copy over the config.php file to new moodle folder (that will be moodle 2.9 files)?
As it could be multitude of different issues showing this error, You may find discussion about similar errors here, and see which solution works for you
https://moodle.org/mod/forum/discuss.php?d=214752
also you may want to check this