You will receive email notifications about theme updates when they are available. We usually upgrade together with the Invision Community. Sometimes theme updates are not necessary when Invision Community releases a new version.  

Normally, there's not a need to upload any new files via FTP unless we explicitly state so in the upgrade announcement.

1) Backup your theme first

Backing up your theme prior to upgrading is always a good practice. In case something goes wrong you can simply re-import your backed up theme going back to how it was before the upgrade.

To do so, navigate to Customization -> Themes in the AdminCP, and click the dropdown menu next to the theme you wish to export. Click the Download menu item, and after a second or two your browser will prompt you to download the theme.

The file you download will have the .xml file extension. This special file contains everything your theme needs, including any images you've added.

You'll want to repeat this process for your child themes as well.

2) Update Invision Community

To ensure your templates are updated properly, you need to update Invision Community to the latest version before updating the theme. Upgrading the theme before upgrading Invision Community often causes problems with outdated templates.

3.) Download the updated theme
Assuming you have an active license, download the latest style updates from the customer area

4.) Update your theme
In the example below we will use our Fantastic theme as a reference.

When new theme updates are released, browse to Admin Cpanel > Customization > Themes. Click the arrow icon to the very right of your Parent theme and select Upload a new version from the list. Browse for the updated .xml file, press Upload and your theme will be updated!

Extract the theme you downloaded from the customer area to the folder using any compression tool and select the (theme.xml) file by clicking the browse button. hen press the upload button.

Your theme is now updated. 

As a result: We made the update through our main theme. When this is done, our child themes will be updated automatically.