Thanks for the reply.
My color filter only applies to the color of the lines, not the pattern, so that is not it.
I started a test project from the out of the box mechanical template, & it displays the hidden lines on the fab duct, so it is a setting within my starting template file.
When I compare the Line styles available in my template to the out of the box mechanical template, the dialog box & the available line styles are different. (see attached PDF) My template was upgraded from an earlier version.
Do you think that is the problem, there is no MEP hidden line style in my template? I tried to transfer the project settings from the out of the box template to my template, for the line styles, but they did not change.
Is there a way to update my template, so it will show the new style dialog box for Line styles?
This makes me wonder if there are other things in my older, upgraded template that are missing the functionality of what is available in the out-of-the mechanical template. Is there a better way to transfer custom settings from an older version of a project template, besides upgrading the template file?