I would try this workaround:
https://askubuntu.com/questions/613401/cannot-connect-dsl-after-upgrade-from-14-10-to-15-04
- [Trisquel-users] WiFi connection problem after installing Tr... anguriamelone
- [Trisquel-users] Re : WiFi connection problem after ins... lcerf
- Re: [Trisquel-users] WiFi connection problem after ... anguriamelone
- [Trisquel-users] Re : WiFi connection problem after ins... lcerf
- Re: [Trisquel-users] WiFi connection problem after inst... anguriamelone
