First of all: I am a complete novice when it comes to TvHeadend.
I had installed it on my QNAP NAS and tried to get it to work somehow.
I created a user on the administration website and then, at some point during my futile attempts, clicked on "login" and then entered a (presumably) incorrect password. I then got a "Forbidden" displayed and that was it.
From then on, when I clicked on TvHeadend on the QNAP home page, a "The website is unavailable" web page always appeared.
This remained the case even after I had uninstalled TvHeadend and then reinstalled it.
Even restarting the QNAP did not change this behavior.
What can I do?