Sounds like icons from a software program. don't delete them but remove them from the catalog. I have had them come up from going into a folder with software and photos in it and lightroom will locate the icons and install them along with other photos.

Be careful, they used to use asbestos in the window putty.

I have a Nikon D7100 and use the lower function button on the front of the camera, Easy to use and I don't have to dodge my glasses.

I have a Nikon D7100 and wear glasses too so I use the function button to focus, it's on the lower right side of the lens. I find it quite easy to use.

Has anyone given any thought to partial color blindness?

Not yet, I hope to in the future as I still have some of my old equipment.

Photoshop CC 2018, Lightroom Classic CC (all the time), Helicon Focus, Affinity Focus, Landscape Pro Studio (occasionally), Photomatix Pro Studio (occasionally) and a few assorted plug-ins

Thank you everyone for your comments and support. I inadvertently said finger when I meant thumb and as I am nearsighted the option to remove my glasses is not available to me. That being said it is awkward placing my Thumb between my glasses and viewfinder meaning it will be a detriment when I want to take a photo on the spur of the moment. For landscape it is no problem and I can work around it. I have programmed the Front lower button for focusing and it seems to be quite comfortable and works the same as the BBF. So now I will use the FBF or as I prefer, the FFB (front focus button).

Thanks for the ideas and thoughts everyone. I think I will do as RWR suggested and program the Fn button to do the same thing.

Do you know if the eyecup would make it easier to access the BBF on a Nikon D7100? My finger doesn't fit between the glasses and the button.

I wear eyeglasses all the time and have a problem using the BBF with them on, they always are in the way, does anyone have any ideas how to work around this problem?

If you can find a file in the missing folder you can locate the folder. In Lightroom go to Library window, open the library file on the upper left, select find all missing files, this will give the last location of the folder/file and the file name. copy the file name click locate and paste in the search box for the file. That will take you to the folder/s that it is in (the missing folder). It also gives the option to locate other missing files in the same folder.

On mu D7100 my eyeglasses get in the way of the BBF so I use the function button instead, works great

O set the function button on the lower front of my D7100. It's much less awkward.

I have a Mac and use iStat Menu which reports fan speed and CPU temperatures, as well as others and I often find, in Lightroom Classic CC, but not the older versions of Lightroom, that my fans run at maximum speed and CPU sensors often are over 200 degrees. With this information, your computer may be shutting down due to overheating, just a thought.