This message is relatively new. (from 2.3.2 ?)
It is a warning message that informs you that OpenGL failed to create the context that you requested.
There are currently two ways (of which I know) to stop this error message:
- make sure that all of context settings are explicity filled in and within range of the graphics card/driver you are using it on (this should be easy enough for your own card), or
- disable SFML's error stream (you only need to do this during the creation of the context/window so can be immediately restored)
I, personally, have taken to disabling the error stream as there's no easy way of finding out the maximum settings available before attempting to create the context.
An example of this can be found
here. The error stream disabling code (the three lines that wrap the context creation) has comments. Hope this helps.
If you would like to know more about the reasons behind this message, you can read
this discussion about it.