AWS Lambda Create Function Role Error

I encountered this and it drove me nuts. In the end I wondered if the GUI was giving me incorrect info, and the role was in fact NOT 'already existing'. I went off and did something else for a couple of minutes, and when I came back everything worked fine with no problems. I suspect it's an AWS console bug.

This is still an issue in 2020!

I choose an existing role or try to create a new one, and I get the An error occured during the creation of your role template. Double-check whether the role name already exists and try again. no matter what I choose.

The only option is to wait for 10 minutes and try again.