I am following "Sandbox:Basic Part Design Tutorial 018"
At the point "After the face is selected, click on the New sketch icon in the toolbar or from the Part Design menu and that will map our next sketch to the back face of the part. Now select Sketcher CreateRectangle.png rectangle tool and place a rectangle on the rear face of the part in a similar fashion as shown below. Now following the steps listed, constrain the sketch.
Select one of the horizontal lines apply a horizontal distance constraint and a value of 5 mm.
Select one of the vertical lines and give it a vertical distance constraint and a value of 11 mm.
Select Sketcher External.png External geometry tool
Select the upper right vertex of the face and click it so you are provided a point from the external geometry to link our sketch to. "
My Sketcher view is of a square dimensioned 36" x 36" on the sketch on the face. I then choose the External geometry tool and move it around the sketch. If I move it near the 36" square, I get a Stop sign icon. If I move it near the top right corner of the face, or bottom right the same. If I go to the actual top left corner or bottom left corner, the white cross hairs remain and I can click inthose locations. But when I do, I get the Report view
"Selected external reference plane must be normal to sketch plane. Failed to add external geometry: Not able to add external shape element"
Here is the file:
Where am I going wrong?
Using OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.4 (GitTag)
Build type: Release
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)