This update changes the updater to ask for permission if the new version's authenticity certificate is not 100% identical to the current version, which will be necessary for the update to 1.3. We normally manage to keep these changes hidden, but time constraints this time around means that you will be shown the change and asked to approve it.
When updating from Open Rails 1.2.1 to 1.3, you will be given details of two certificates. Please check that the details for the "subject of certificate" are as follows and then select "Yes" to recieve the update.
Here is what the message will look like: