Unable to complete multiple direction extrusion

Here it is, Dave's question of the day!

I'm following a tutorial on building a V12 engine (a tutorial with loads of missing info) and once again I find myself stuck.

For some reason, I cannot complete the multi-directional extrusion as explained in step 9. Now the tutorial was done on a SW2012 edition and I'm using SW2016 but I don't think the procedure would change between those editions. Below is a short excerpt from the tutorial showing the few steps leading upto step 9 and I have also attached my model. Step 6 and 7 are complete and step 8 I think might be part of the problem (I don't know) Please tell me where I am going wrong this time?

1.    Step 6

open a
sketch under the body and draw this sketch

1.    Step 7

extrude
it up to top plane

1.    Step 8

open a sketch on the right plane. use convert entities
command

1.    Step 9

extrude
the last sketch in two directions. direction 1 is up to body and direction 2up
to purple surface

All very clear as mud!

Dave.

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