Comment 14 for bug 1173372

Hi, I had the same problem in Ubuntu 18.04 Beta2.

What I did was to find the bcmwl related tasks("ps aux|grep bcmwl") and I found there was one something like "rmmod [....]bcmwl" blocked.

I killed it(sudo kill -9 [pid] and I could continue. Now I have upgrade the system.

I think it happened to me by canceling the installation of restricted drivers.