A PHP Error Severity: Notice Message: session_write_close(): Skipping numeric key 0

The keys in the $ _SESSION associative array are subject to the same limitations as regular variable names in PHP,
ie they can not start with a number and must start with a letter or underscore.

For more details see the section on variables in the PHP manual.

Or you did not follow the upgrade right.

What did you Try? What did you Get? What did you Expect?

Joined CodeIgniter Community 2009.  ( Skype: insitfx )