Problems with eraser toggle button

Hi. Complete beginner here. I’ve been configuring buttons on my new Huion 16 2021 and have gotten stuck when it comes to the pen. I went to use the eraser toggle shortcut which is assigned to the lower button on my pen and it doesn’t toggle the eraser mode. I then went to manually click the button with my pen nib and it still doesn’t turn on. I’ve tried it with multiple pen presets and the button won’t turn on. It just stays grey. Help! Am I being really daft or is there something I have to do to activate this button.

Can you share a screenshot of your Krita, where you trying it? The only way I can make the eraser button disabled so it can’t be interacted with in any way is when there is no document open. Only after creating or opening a file in Krita the eraser button can be used.

Well this is embarrassing, but also good. I closed the program and went back into it and it’s working now. Thank you for replying though!