can i update ci version Upgrading from 3.0.0 to 3.1.5

can i update ci version Upgrading from 3.0.0 to 3.1.5

You should follow the upgrades in sequence.

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

Joined CodeIgniter Community 2009.  ( Skype: insitfx )

Every Upgrading From a Previous Version after 3.0.0 starts with the same "Step 1" task which amounts to

Replace all files and directories in your system/ directory.

If you have any custom developed files in these directories, please make copies of them first.

Using the files for v 3.1.5, follow that instruction.

Then, go through the following upgrade instructions, doing each Step where Step > 1

Upgrade 301
Upgrade 302
Upgrade 303
Upgrade 306
Upgrade 310
Upgrade 312
Upgrade 313

All other upgrade pages only have Step 1.

Just to add to Dave Friends detailed answer above, it is very quick when you get on with it and is very simple. The CI team has gone to great lengths to document changes and usually involves nothing more than overwriting files.