Hi there,
I’m experiencing the same issue!
Do we have any clear understanding of this strange behaviour?
In my case, it happens mostly on Safari, and it seems like it’s something related to actions that save/load data from cookies / Current User when it is not logged in.
Any news @emmanuel ?
Thanks for the great work.
Hi, I am having the same issue, any ways to solve this problem yet?
Hey @sizheh 
I used to get this message a lot when I would try logging in when my user was already logged in. It might be something different, but might as well give it a try anyways. Doesn’t hurt right?
So what I do to fix this is just on page load, if the user is logged in, redirect them to the correct page. Then your user won’t try logging in again if they are already logged in. Or on the login button, if they are already logged in, just take them to the page instead of logging them in.
Hope that makes sense! Let me know if it works.
Hope that helps! 
For All Your No-Code Education Needs:
I know this post is old, but I’m getting this error now in Safari. If I try and hit the logout button in Live I get this, and when I was trying to test signing up a new user in development mode I kept getting it. I’m concerned since it’s an issue on both Live and Development mode.
Has there been any fixes to this?
Same stuff.
same issue. we moved to a subdomain - and now - no user related actions work. Users cant even log out.
