If you are using a modded BIOS on your AMD Polaris card, and try to install AMD's excellent Crimson ReLive drivers, you might be in for a surprise. This is because AMD re-enabled their BIOS signature enforcement with these latest drivers. Basically, if you modded your card's BIOS in search of higher overclocking, more voltage or customized fan settings, the hash in your BIOS is no longer recognized by AMD the driver, since it differs from the factory values.

On detecting such a modded BIOS with an invalid checksum, the Crimson ReLive driver won't load, meaning that the system will run with the VGA fallback driver only, without 3D acceleration and Radeon Settings will not start. However, you can force your modded BIOS to load on Crimson ReLive if you're willing to jump through some hoops.Overclock.net user asder00 posted a pretty nifty guide that enables the user to install a modded version of Crimson ReLive's 16.12.1 drivers, with a modified kernel that doesn't include the BIOS hash check. His work, based on lordkag's own, makes use of the mentioned modified kernel driver and Pixel Clock Patcher, enabling you to access Crimson ReLive's features even with a modded BIOS:

asder00's workaround:

• Download the modified kernel driver here
• Download the Pixel Clock Patcher here (needed for the windows driver signature workaround)
• Navigate to the AMD driver extraction directory, usually "C:\AMD" then go into" Win10-64Bit-Radeon-Software-Crimson-ReLive-16.12.1-Dec7\Packages\Drivers\Display\WT6A_INF\B309333"
• Extract the modified kernel driver in the "\B309333" directory overwriting the file
• Uninstall current AMD drivers normally and DO NOT REBOOT when asked
• Reboot with advanced options like so:
• Press and hold the Shift key on your keyboard and click the Restart button.
• Choose Troubleshoot > Advanced options > Startup Settings and click the Restart button.
• When your computer restarts you'll see a list of options, press F7 on your keyboard to select "Disable driver signature enforcement".
• This is needed only ONE TIME to successfully install the modified kernel, in the next reboot the driver signature enforcement will return to normal.
• Install the driver normally with setup.exe in C:\AMD\Win10-64Bit-Radeon-Software-Crimson-ReLive-16.12.1-Dec7
• DO NOT REBOOT WHEN ASKED
• When the installation is finished run the atikmdag-patcher.exe (this will take care of driver signature for windows so we no longer need to disable the enforcement with F7)
• Press yes to patch the file
• When finishes reboot the PC and enjoy your modified bios

The patch has currently only been tested on the x64 version of Windows 10. AMD could, in a future driver version remove the active BIOS hash checking from their driver suite (which they historically did before) but whether that will or won't happen is something only those at the red team know.