The error occurs when the Database you are in has received an error whilst communicating with the services responsible for storing the Crystal Report documents.
The first thing to try is to close and reopen the Financials tab.
In the Financials tab title, click the vertical three dots icon and select Close.
To re-open Financials, in the top left, click the nine dots icon and select Financials.
If this has not resolved the issue, please raise a new case online and reference the title of this article. Please include the Ledger you are in when encountering this error.