I did a search for this topic but wasn’t able to find any results. I’m drawing in Top view, parallel projection in SketchUp and the line doesn’t show when I draw only after I click to end the action.
A couple of things I would check/try.
Save and restart the model.
Adjust the Opengl settings found at Window/Preferences/Opengl
Check your graphic card driver to see if there is an update.
That was actually on a different machine. (And actually I still have that problem. I think it had gone away but might’ve come back with an apple software update or something.)
I have the same issue - drawing top view, camera parallel projection ie effectively 2D. Mac 10.11 (just jumped up from 108.5 - same there) - on a Mac Mini. It is the ‘fill/face’ that blocks the view of the line/guide - delete this and you can see, but each time you draw a line of course you create a new fill/face. Fiddling with OpenGL makes no difference. I’m using ‘Hidden line facestyle. White background.’
This suggests that you are changing the active tag, you shouldn’t do that.
Leave untagged active, draw everything there then only assign tags to groups, components, dimensions etc. Never assign a tag to Raw Geometry.