NVIDIA has paused the Marshmallow update for the Shield Tablet after several users reported losing Wi-Fi connectivity after installing the update.

Says NVIDIA:

We have temporarily turned off the OTA update until we understand why a few users are losing WiFi connection after updating their tablet to OTA 4.0. For any users unable to recover their WiFi after performing an update, can you please try the following troubleshooting steps and let me know if any of the solutions worked for you:

-Reboot your tablet 2-3 times. If this fails, power cycle your tablet 3-4 times (not reboot but complete power off). If this does not work, charge your tablet to 100% and attempt again a couple of times or so. -Factory reset your tablet. Make sure you backup any important files before you perform this step. -A couple of users reporting their WiFI coming back after leaving their tablet powered off for a few hours. Try leaving your tablet powered off for a few hours and then turn the device back on.

Following the troubleshooting steps mentioned above seems to fix the issue for most users, but if you're still not able to connect to Wi-Fi networks, send a screenshot of your tablet's Advanced Wi-Fi page (Android Settings -> Wi-Fi -> Access the menu by clicking the three dots on the top right hand corner -> Advanced) to driverfeedback@nvidia.com.

Are any of you facing connectivity issues on the Shield Tablet after making the switch to Marshmallow?

Source: GeForce forums