I’m having that same issue on OSX: message keeps coming back and there is no option to remove the service in the preferences. I looked through the split topics but haven’t found a solution there. For one thing, relogging in Tidal does not seem to change anything.
Sorry, I’m very late in replying to this. Your solution worked. I then put the content of the cache back and got the same issue. I then removed the folders labelled “Tidal”, and was able to logout normally.