Camera far clip above a certain size gives error messages only when the cursor is within the game window?

So I've stumbled upon a somewhat interesting problem/bug? Long story short, big real size space world (with a custom coordinate system to avoid float precision problems), using 3 cameras to avoid z-fighting. However, on the camera at the very back I need to go from 500 000 near clip to 1E+10 or so far clip, but the moment I set the far clip to anything higher than 1E+07 I get a big lovely error thrown around that doesn't really stop me from doing anything, it just clutters the debug log. The error is the following:

Screen position out of view frustum (screen pos 1693.000000, 1289.000000) (Camera rect 0 0 2707 1305) UnityEngine.SendMouseEvents:DoSendMouseEvents(Int32)

This error only occurs when I have the mouse within the games window, if I for example drag the mouse to the side and control the game with a controller no errors are shown, but the moment I place the cursor somewhere within the game window I get completely spammed with this error. It shows up both in editor mode and when I play the game, so its quite hard to ignore. Since the game can still be played without any problems at all, does anyone know of a good way to either just turn this error message off or of course fix whatever the problem could be (without lowering the far clip distance)?