The flashing Not Allowed sign usually appears when your input devices aren’t working correctly.
Why Does the Not Allowed Sign Appear?
This alert is usually supposed to appear if you repeatedly enter invalid inputs.
Unfortunately, the alert has a habit of showing up when it isnt supposed to.
The cause can also be a faulty input gear.
Worst of all, it often impairs your ability to pop in and use your PC.
Luckily, its a completely fixable issue.
You should start by checking your input devices and keyboard keys.
Unplug and replace your keyboard, mouse, and any other devices that provide input.
Check whether your system continues to show the Not Allowed alert even after youve unplugged those devices.
Enter the unit event number associated with your keyboard, then wait to see which inputs your keyboard registers.
Next, pressCtrl + Cto end the active process.
Youll need to fix any keyboard keysthat evtest reported inputs from when they werent pressed.
Alternatively,try remapping the key.
Reboot your PC and wait for the boot selection loader to appear.
Next,select a different version of the Linux kernelfrom the list provided.
preserve your new selection and reboot your PC.
Once your system starts, you should observe that the issues with the Not Allowed alert completely disappear.
