My Lightroom 5 suddenly has a grey bar across the image in edit mode

[#1]

I am still using my downloaded Lightroom vers. 5, now on my 16'' Macbook Pro from last spring. I haven't opened it in maybe a month and now it looks like the attached image. Can it be due to software upgrades on the Macbook? 

[#2 · Accepted solution]

I suspect that you are on Big Sur.

Older versions of Lightroom are not supported on Big Sur, and if you uninstall LR5, you will not be able to reinstall it.

I suggest that you subscribe to the Photography plan, which will give you the latest version of Lightroom Classic.

Using unsupported software can lead to display problems like the gray bar on the Image info overlay.

To hide the overlay, press the I key on the keyboard once or twice.

[#3]

Thank you, Per!

You are spot on - Big Sur and pressing the I key twice helps. I edit maybe 50 images in a whole year so a monthly subscription is a bit steep for me.