Slice Button in Cura is missing

[highlander_kjm 0]

Newby question.  I create a simple design in tinkercad (cylinder, one with and another one without a hole).  I export each as an stl file.  When I open each of them in Cura, the slice button is not available.

 

What am I doing wrong?

 

TIA

[highlander_kjm 0]

I restarted Cura and it now works!

[Flying_Roger 1]

I have installed CURA 5.1.0 today and I experienced the same problem.
It worked with a model, but I got a "slicing error" after loading another STL file and then the slice button no longer appeared, even if I cleared all and reloaded the STL model.

Also solved by restarting CURA.