The eyedropper tool has suddenly stopped working. I tried resetting preferences and restarting PS, I've tried resetting the tool, I've also just run the most recent update - none of these have worked. If I try to select a colour with the eyedropper it shows as white. In the colour mixing dialogue box the colour shows as 'ffffff'.
I'm new to PS, so any suggestions would be gratefully received. And of course I have an imminent deadline - software always plays up when you have a deadline!
Do you have a layer mask selected in the Layers panel where you might be selecting the white? Can you show us a screenshot of your full screen including your Layers panel?
I don't have any layer masks...
There's a button called 'Edit in quick mask mode'. I pressed it and now the eyedropper works. No idea why. In case anyone else has the same issue, the button looks like the Japanese flag or the EU flag when you press it...
That makes sense. Quick Mask mode (which can be accessed by going to Select > Edit in Quick Mask Mode or by the keyboard shortcut Q) adds a temporary mask. Your layer in the Layers panel should be highlighted red and if you go to the Channels panel, then you'll see a new channel selected below the others that is named Quick Mask. When you have a quick mask, the eyedropper will select the color of the mask. If nothing was selected when Quick Mask was enabled, then the mask will be completely white. White areas are visible parts of your layer. If you had a selection active when enabling Quick Mask mode, the areas outside the selection would be black. You can also have variations of gray if the selection was feathered when enabling Quick Mask mode. To revert from Quick Mask back to your image, press Q again or go to Select > Edit in Quick Mask Mode to deselect it (when it's selected it'll show a checkmark beside it).
Thank for the info'. A quick question... If I made any edits to my document during Quick Mask Mode, what would the consequences of that be? I didn't enter that mode deliberately, so I'm not sure how long I was in it.
When you're in Quick Mask mode, you can use drawing tools like the Brush tool or the Pencil tool to draw what would become a selection once you exit Quick Mask mode. If you had drawn anything and then exited Quick Mask mode, then you would see what was drawn become a selection that would appear as marching ants. If you didn't want the selection at that point, then you could deselect it by pressing Ctrl (PC)/Command (macOS) + D or going to Select > Deselect.