Clone Stamp Tool Error (Alt-click does not define source)

Hello. I have come upon a very frustrating problem that I can't find any answers to, despite a lot of googling.

I am very new to Photoshop and I am learning how to use the clone stamp tool by following various tutorials, however I get stuck with the following error:

"Could Not Use Clone Stamp Tool Because Area To Clone Has Not Been Defined" and then it tells me to Alt-click to define the source. However when I do that, I get the error again!

I have tried:
- To reset the tool
- Made sure all layers were selected (It initially gave me an error for that)

- Made sure the layer isn't locked.
- Reinstalled Photoshop
- Tried to see if it was somehow not the alt-key I needed to use but I can't find any other key that lets me do this.
- Closed all other programmes besides google chrome to see if anything was conflicting

I use Windows 10, my computer is brand new and powerful, I have a wired mouse and keyboard.
The only thing I seem to be able to conclude is that my Alt key is not working probably in Photoshop, but it works fine in other contexts. I can also still alt-tab between programmes when I have photoshop open. My keyboard is nordic as I am from the nordic countries.

I was initially working on two layers but since I was having issues now I am just working on one layer. I am really at a loss as how to solve this, it is the first time I ever have to use the clone tool and right away it gives me this error. I appreciate any help you can give.