Engraving options panel caret disappeared

can someone tell me how to make the left hand side engraving options appear again? the caret that toggles the panel has disappeared completely in one of my files and I cannot figure out how to make it visible again.

I’m on deadline for a project and this kind of ridiculous glitch is really challenging to deal with. I literally cannot open the panel that I need to use right now.


The top button in the Engrave toolbox hides/shows the left zone: the button that looks like a square with a white strip on the left edge.