A exception about the mouse

[sssste]

Hi,there
I start to use kubuntu yesterday, and after I install Nvidia driver, and my mouse went wrong ,when i tried to click or roll my mouse, it would showed as which in the pictures.My display card is GTX 950M and i install the driver NVIDIA-375. What should i do? Thanks

[sssste]

sorry,here is the picture https://i.loli.net/2017/08/21/599ad0777d676.png

[sssste]

i fixed it by changing RenderBack-ends to Xrender