SESSION: ci_sessions database table not populating

Is there a Session.php file in the root of your /system/libraries/ directory? If there is, then you have missed the step of deleting the contents of the directory before copying over the files from CI3.

If there is not a Session.php file in the root of your /system/libraries/ directory, then your error message should have at least changed. If it did not, then make sure you don't have a Session.php file in your /application/libraries/ directory. Of course, this would imply that you were using some sort of customized Session library before and you may still have other issues to resolve in migrating to CI3.

**SOLVED**

You were right. The problem was with my WAMP testing server. Though i was changing the files i uploaded to WAMP, if a directory or filename already existed on the WAMP testing server the previous file was never overwritten. By going into WAMP and deleting everything on the testing server then uploading again everything seems to be working fine now. I've also tested it outside of WAMP by putting the pages online and everything seems to be working. Thanks for your help.