Attempting to report one of multiple bugs with your web player at
https://community.spotify.com/t5/forums/postpage/board-id/WebPlayer
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I am logged in on the forum. The forum seems to be full of people posting bugs stating that it's impossible to report bugs, which are then marked as solved, resulting in more people posting more bug reports about the inability to post bug reports. I suggest you stop using the lithium forum software, as it is very buggy. Also I notice that I had to create a new username and account even though I am logged in to spotify because you are not capable of implimenting a basic single sign on solution.
The actual bug report I was orignally trying to make was that using the web play in firefox is also quite buggy, especially the search results which provide very pretty results with play symbols which interact with my mouse in a subtle yet engaging way when I roll over the result, but clicking does absolutely nothing, not even in the console. I suggest that you do some browser testing and maybe use something slightly less recent than the latest bleeding edge javascript framework that makes the devs all frothy, and it might actually work on more than the identical chrome on mac setup that your team uses. Also, unit tesing is not a substitue for actual browser testing.
Finally, all your designs is full of mystery meat navigation which I though the web had given up on in the 90s. Maybe it's a retro thing, I don't know, but I have no idea what any of the buttons do and I have to click around to see what happens. I now own a llama farm in Patagonia, which is actually my second one, which I learned in the past is a good reason not to click on symbols on the web you don't understand.
OK, I lied about the llamas, but your software is very buggy, and pretty much guarenteed to be very buggy because almost no one can report the bugs.