Why do I get "some services are currently unavailable" so much?

[Mattys1]

Currently trying to open an email I sent from the back end of my pos terminal and it just says "some services are currently unavailable". I've also received this response on other items.

[Rob]

This issue seems to be related to the network. Please try refreshing your web page and clearing your cookies. Additionally, it's best practice to make updates on a computer that can push changes to the terminals. If you make changes on a terminal that pushes updates to the computer, it may take longer for the system to update.