Plasma fails to start when using old video driver (e.g. vesa).
The same happens when X server is using dummy driver (e.g. I want to allow PC be properly booted even when no monitor is attached, to make it accessible with VNC).

On start plasma displays the following message:
"Plasma is unable to start as it couldn't correctly use OpenGL 2.
Please check that your graphic drivers are set up correctly."

The biggest disappointment is that plasma displays this message in nice graphic window. I could understand if that message would appear in stderr/log file -- that would mean that the driver is really unusable.

Desktop effects are turned off, of course.

Reproducible: Always

Steps to Reproduce:
There are to proposed ways to reproduce that:
A -- by downgrading your graphics driver to vesa. Determine which graphics drivers are currently in use, and then disable them (either by blacklisting or by uninstalling correspondent packages). For example, I reach this state when I uninstall the persistently hanging xserver-xorg-video-nouveau package (but binary NVIDIA packages aren't yet installed).
B -- by forcing your X server to run without monitor and then connecting with VNC:
1. Install and turn on the dummy driver on server (as per http://ubuntuforums.org/showthread.php?t=1452600&page=7&p=11419677#post11419677).
2. Connect with SSH to the server, install x11vnc package and launch x11vnc.
3. Connect to the server with xtightvncviewer.

Actual Results:  
The "Plasma is unable to start as it couldn't correctly use OpenGL 2.
Please check that your graphic drivers are set up correctly." message in the graphic window.

Expected Results:  
I expect plasma to be working. Maybe slowly, maybe with glitches. But somehow working.
Is kwin is able to display windows, then plasma should be able to display widgets.