I ran into this after I started trying to configure a second instance of HA running on a second network, but both accessed with the same hostname (homeassistant.local).
Clearing cache isn’t enough; I had to clear all site data (specifically cookies and/or database which is where the ingress authorizations are stored).
Clearing cache isn’t enough; I had to clear all site data (specifically cookies and/or database which is where the ingress authorizations are stored).
Can confirm this worked for me.
I fixed my instance by restting the configuration for the add-on (Home Panel in my case) and upon logging in I changed the default homeassistant.local:8123 URL to the IP address of my HA docker and it resolved the issue. Looks like a DNS issue?
Can also confirm clearing cache and site data (in Firefox) worked for me.
Was also getting this same issue, many if not all addons were throwing 401: unauthorized errors. Clearing the ‘Site Cookies and Site Data’ in Firefox (hitting the padlock in the URL) resolved the problem.
Ingress suddenly stopped working, and I was getting an error 401 from all add-ons that have a web UI - such as file editor, terminal, etc. In my experience, after 40 years of IT, errors can usually be traced back to a change you mde, no matter how innocuous. I recalled changing a DNS pointer to a stealth pointer a week ago… basically i point my domain https://twosquarefeet.ca to https://twosquarefeet.duckdns.org. A standard URL pointer leaves my http header to contain twosquarefeet.duckdns.org and that appears in the address bar. Stealth mode hides the duckdns redirect, I assume by putting https://twosquarefeet.ca in the http header, and this appears in the address bar. I have an old domain with a standard (not stealth) URL pointer, and this works. So it appears that a stealth URL pointer on a domain breaks ingress. Sure enough, browsing directly to https://twosquarefeet.duckdns.org works too.
Could you please share where this setting is? I have the same issue with Home Panel.
I tried using edge and it “worked” for a moment… but when I logged in to Home assistant got the same 401 error
Can confirm this too, clearing cache on Chrome does the work.
I just ran into this issue with Firefox. Everything working fine then all of a sudden 401s on any ingress addon. WARNING (MainThread) [supervisor.api.ingress] No valid ingress session None in the supervisor log.
Tried clearing cache, all site data, close, reopen etc. Didn’t work. Started looking through the settings. I changed the following from Strict to Standard and now we’re all good in the hood. I had not changed this setting previously so I don’t know what gives, but it did fix my issue.
Just an FYI if anyone else runs into this issue.
Thanks. You probably just saved me hours of time.
Edit:
Here’s a way to disable protection for a specific URL:
Edit 2:
Just to see if I could reproduce the original issue, I recently tried turning Enhanced Tracking Protection back on. When I do this, Ingress and the add-ons still work, although I don’t I don’t know why.
Life Saver You 
Thanks 
Saw the exact same thing on Firefox 90.0.2 (64-bit) on Windows: Ingress was just blank and I got a 401-response. I could not see ingress addons when accessing Home assistant on my LAN through the mDNS-address (http://homeassistant.local:8123). However, ingress worked when accessing the HA through HTTPS (https://example.duckdns.org), as well as when I used the LAN-IP directly (http://192.168.0.X:8123).
I struggled for hours. In the end, it was sufficient for me to remove the cookie called ingress_session. Thank you for the help!
This worked for me! Thank you! I’ve been researching this for a couple of weeks now and your solution was so simple. I ended up reenabling to Strict and the add-ons’ pages loaded perfectly fine still.
There’s an official alert for this issue now
I had the same error. After reading this post I thout that the cookies of home assistant were giving the problems. I deleted these cookies, and now it works like a charm
Cross posting from Discord to here:
Seems like I figured it out (for my situation.) Would be good to document it somewhere, let me know if that’s wanted, and I will.
In short the issue is that FF only allows cookies from the originating server. This can be changed by the parameter “Network.cookie.cookieBehavior” under “about:config”. Set it to 0 to allow all cookies and ingress should now work after a page refresh. Network.cookie.cookieBehavior - MozillaZine Knowledge Base
Thank you very much - for me this saved my day!
For me, clearing site data was not enough; I had to use my phone to clear all other sessions (clicking on your account name in the side bar then scrolling down). After logging in again, the addons work again.
