Wireless connected but no internet access

Well, I ask at ubuntu forums and they answer very fast and it worked.

Click on Network Manager> 
Click 'Edit' 
Edit the wireless connection>
Click the IPv6 tab>
Set IPv6 to ignore>
click OK>
Reboot.

If you have an Android phone you can also use it as a Wi-Fi adapter... I had to do this a few times and it works very well.

• turn off mobile data on your phone.
• turn on USB tethering (don't just turn on personal hotspot as it turns off your phone's wifi).
• that should bridge the connection between your phone and PC.