Not sure if this turned out to be your issue but in my case, I was able to solve it by going into
options
then display tab 
then you will find a column display resolution
and there you will see arc and circle smoothness. 
(Previously I entered the number 1 not long after installing CAD - not thinking anything of it at the time) 

I can't say for sure which number would be the best option. But I entered 2,000 
- My unprofessional guess would be " The higher the number, the smoother it will be (OBVIOUSLY) but I would also guess that the more strain it would put on your computer resources since it is (in theory) constantly trying to keep it at the higher level of smoothness if you so choose" - So instead of entering the highest number > 20,000, I went with 2,000

After I changed it from the number 1 to 2k, I applied the changes and I could immediately see the linetypes once again re-appear on the lines that I had drawn and in return, my sanity resumed its normal course. 

It's worth noting that there is a chance that you might have to regenerate the drawing *REGEN* to ensure that all lines, arcs, and circles reflect the changes if they have not already done so. 

Again, I'm not sure this was your specific problem and the settings might be different on a MAC but it definitely prevented my potential result of becoming bald.

(See images for further direction)