NOTE: Make sure that you are migrated at least to V2 of the resource editor.
If you perform changes to ressources (documents, payment page layouts, e-mails, etc.) Make sure that you publish your changes once you are done in so called snapshops. This allows you to change and preview all you modifications. Once you are happy with the changes you can publish them all at once using the snapshop feature.
The resource editor shows on top if you have unpublished changes. The screenshot below shows an example of how a snapshot can be published.