Recently switched over to Lightning from Classic. Got this error in testing but never able to replicate it.
Assumed it was an issue during development but now a user is getting it in Production when clicking on the Lead tab which loads the Recently Viewed.
The record type shown isn't complete, it is missing the last 3 digits but the first digits correspond to an Account record type.
I can't recreate this error. I tried logging in as the user that is getting the error message, but it doesn't error out for me.