Where is the "slice" button in Cura? I'm relatively new to Cura, having just installed it a few weeks ago.  I have 3.0.3 and I'm running on Windows 7 64 bit.  I noticed the auto slicing setting while poking around the settings.  Auto slice almost always works.  

A couple times now, Cura won't auto slice. I can't seem to find the slice button.  How do I manually slice?  I found an article on how to disable auto slicing, but it doesn't show how to manually slice.

Where the button "save to file" is is greyed out and just says "Print with Octoprint".

Closing Cura and re-opening it will fix the issue.
If auto-slicing is disabled, the button in the bottom-right corner of the window toggles between "Prepare" and "Save to File" depending on whether the model needs to be re-sliced or not. While slicing is in progress, it changes to "Cancel".

If auto-slicing is enabled, the button always reads "Save to File", and is greyed-out when slicing is being performed (it does not change to "Cancel").