Hi Florian
I know, I am 3 years too late, but I will answer this post anyway, who knows maybe you or somebody else still has this issue.
I actually faced the exact same problem you did, also wanting to create an invisible Course.
So what's the problem with those excludePatterns?
Patterns are combined using an OR-Operator. This works perfectly fine for include-Patterns, doesn't really get us the solution we expect when using excludePatterns though. (As smeyer told me in this Bugreport: http://www.ilias.de/mantis/view.php?id=16920 )
How can you fix this?
Use only one excludePattern, doing the thing you want altogether. You can use Regex for this. In your case this would have been the following solution:
<excludePattern preg="^(il_crs_admin|il_crs_tutor|il_crs_member)"/>
Please note that in your specific case, you would even have a simpler solution, since all of the roles you want to deal with, and only those roles begin with "il_crs_":
<excludePattern preg="^il_crs_"/>
Hope that helped.
Kind regards
Gabriel Comte
studer + raimann ag