This is a ratio of how many devices (APs, routers, etc.) on which Client Monitor failed to start compared to how many were tried. So the number 81 in black is the total number of Aerohive devices for which Client Monitor was requested to start while the number 3 in red are how many devices for which the HiveManager failed to start Client Monitor. This is typically due to the Aerohive device being disconnected from the HiveManager.
These messages are more frequently seen when you do not specify an Aerohive device in the "Associated Device" dropdown box. This is because when "All" is selected, a request is sent to each device to start Client Monitor for the specified MAC address since the HiveManager does not know to which device the client is associated. This means that even if an Aerohive device is currently disconnected from the HiveManager, a request to start Client Monitor regardless, which causes a failure.
When you specify the "Associated Device" from the dropdown box of all of your devices, HiveManager only sends the request to start Client Monitor to that device. So unless you are specifying to start Client Monitor on a device that is currently disconnected from the HiveManager, you are usually less likely to see these messages.
Long story short, the red count is not indicative of a serious issue, simply that the device on which Client Monitor was attempted to be started was disconnected or otherwise unavailable at the time. Clicking Recover will resent the request to start Client Monitor.