I can not use terrain edit and model viewer

An message “OpenGL context not Started” is displayed.
on jME3.0
why? Please Help.

Try going to (on the upper side of the jmonkey window):

Tools -> Options -> Opengl -> Use Heavyweight canvas [X].

Thank you to advice.
I tried it. but jME3 stopped rebooting.
I try delete jME3 from computer, reInstall jME3.
Update 3.0.0 to 3.0.2
but it does not salve yet.
My computer spec too low?
(hp compaq ds 2510)
I’m sorry My English is strange.