1) In which version of wordpress you’ve tried the plugin?
2) Have you installed the plugin manually or automatically?
3) Do you have tried the plugin in another wordpress installation? If not, can I ask you to try?
I apologize for that, I will do everything possible to try to solve the problem.
1) My version is always current.
2) Manually
3) I have no other domain
Ok,thanks for your cooperation.
1) Have you already tried deleting and reinstalling the plugin? If not, please do it. If you don’t know how do it, I can explain it.
2) Are there another plugins installed and activated? If yes, can I ask you which? Or can you disable all and try to activate just Ubecube 3D plugin?
3) Is there active a custom theme? If yes, you can activate “Twenty Twelve” theme and then try to activate the plugin again?
I know they are tedious procedures, but are necessary to exclude some common problems.