Thaks @Carl Love. I did it

Thank you. There is no error while code working. But after code worked, normally I want to plot a 3d graph. But here there is an error as "Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct". I tried plot3d(Solution(x,t),x=0...1,t=0....1)  and plot3d(Solution,0....1,0....1)

But didn't work.

Space_Fractional.mw

Can you help me again? And thanks for everything. 

@Carl Love 

1- the cursor doesn't move. Stay after semicolon ; . 

@ismonder 

When I save the worksheet, there is an error as image 2. After all, when I opened the saved file, my codes which are not working didn't appear. (Picture 1)

@Carl Love 

as you see plot, diff and lim didn't work. I press enter, nothing happens.

@Carl Love 

that is my simple code. and I realized that I cant save file. When I click File button, Save option isn't enable. There is no error while I'm installing app. I click "Enter" key, nothing happens.

@Thomas Richard  sir, I didn't write. It works only 3+3 example. I writed diff(x,x). I saw these example on web. It didn't work.