If your system has multiple locations set up and someone is seeing this error:

They likely haven't been allowed access to financial data for the location they're trying to access.
The setting for this is found in Booking Dashboard > Setup Locations, under the list of Existing Locations.
This is set on a per-user basis, using the checkbox between each user and each location to determine who can see financial data for where.
To allow a user access for all locations, use the tickbox to the left of their name to automatically tick all locations for them.