No debug token available:
[?] Would you like to upload the log? [y/N] y
* Using curl for transmission.
* curl failed, contact Pi-hole support for assistance.
* Error message: curl: (22) The requested URL returned error: 500
[✗] There was an error uploading your debug log.
Please try again or contact the Pi-hole team for assistance.
A local copy of the debug log can be found at: /var/log/pihole/pihole_debug.log
I too have got the same issue today upon my update of Pihole,
It was stuck for half an hour on "dns unavailable",
I interupted the update, then restarted it, and it seemed to work fine,
But after it finished, I had no access to anything on or outside my network (since my router forces my devices with a DNS server (Pihole) that was now no longer working)
And now Pihole's Web interface is stuck on 403.
Well, How do I explain this now ...
I just reloaded the web page, and pihole's Web interface showed up, but I couldnt login, I go and check pihole's debug, and it now shows no red marks or errors (I did not restart the RasPi it is installed on, I had just disabled the Lighttpd service a while ago as per another help I checked somewhere in here, but it did not originally work.)
Only problem: I couldn't login using my old password, so I had to sudo pihole setpassword
Other than that I seems most of the configurations and such are still in place, only exception was the DNS setting in PiHole were all off.