I rebuilt it before and I did it now. And it doesn't work. Also, I don't think my computer needs regular cleaning and maintenance! I keep it clean and tidy myself without the use of tools like CCleaner. I don't even trust those tools. I keep plenty of space on my SATA HD, it's defragmented automatically regularly, the SDD seems to be ok (and not full), I have 16gb of RAM and if I install a virus or malware scanner every few months, it encounters less than 10 minor things.
I forgot this is what that panel is supposed to, yeah. I've been using it to pin my own programs instead of letting it populate automically by whatever I open. But even so, the max number of recent programs there is set automatically to 10 bij StartIsBack. I never touch that option. I dó muck around in the registry, not with those tools but with registry edits. I wonder if it's any of these. I háve been using this same list on my previous laptop and StartIsBack also had one blank icon on that laptop after a install. It's also always a new icon I add after a certain amount.
I guess I could re-enable all the edits (I also have the restore fixes for every single one), then see if the icon returns. If so, enable one and restart and repeat until I find one is causing it. But that would take tons of time.. I don't think after enabling the culprit regfix the blank icon will appear right away, because after installing a new program it retains it's original icon for at least a few hours or so.