After upgrading Platform, you have to re-install your add-ons and re-configure them.

Check the version.

The old add-on version might be compatible with the new Platform version, or not, so it is recommended you always install newer compatible version if any.

Before installing an add-on, you can use describe command to check its versions. The command usage is documented here.

You can also find the compatibility information at this page.

Check the configuration.

If the add-on version does not change, typically you just need to copy the old configuration. Otherwise you are recommended to check Add-ons Guide for configuration changes.

Check if any extra upgrade step required.

Any add-on that requires special upgrade will be listed here.