Hello there
Since you appear to be a fellow Vista user, I decided to help and investigate...
Two major issues for me: 1) I don't know any Polish, 2) (obviously) I'm not in Poland currently...
I had to use a lot of Google Translate to decipher all these messages (in Polish) I was presented with and to be able to click the right on-screen buttons... I then had to find video content that wasn't geo-fenced (restricted to Polish IPs, only ); I think I settled for
Ameryka-Marzen-Odcinek-12
I tried a variety of browsers on my Vista laptop, but to no avail; I suffered exactly what you reported, i.e. a black rectangle in the supposed place of their embedded player...
I then kindly asked my sister to test that URL on her Firefox Quantum v61.0.2 (32-bit) copy on her Win7 SP1 64-bit laptop: she had to temporarily disable uBlock0 on that site, but, lo and behold, the programme started playing in an HTML5 player...
After some further troubleshooting I did, I think I've solved the riddle: That (nasty!) Polish site performs User-Agent sniffing and simply doesn't like the Vista (NT 6.0) part of the UA, so they decline to load their player on Vista machines (didn't test, but I'm sure the same fate is reserved for XP, too, i.e. NT 5.x)
The solution I chose was to apply a site-specific-UA-override (SSUAO) for "www.ipla.tv" to mimic Fx 62 (due imminently) on Win7 OS; in a "roytam1" browser (NM27/28, Serpent 52.9.0/55.0.0) open about:config and create a new string pref with
name=general.useragent.override.www.ipla.tv
value=Mozilla/5.0 (Windows NT 6.1; rv:62.0) Gecko/20100101 Firefox/62.0
restart browser, clear cookies for "www.ipla.tv" and reload VOD page; you are then presented with
so you have to disable adblocker (ublock0 in my case) and reload ; after reloading, you have to literally sit in front of at least 3min worth of ads; if you change to another tab, the ads and time counter are paused and only resume if you focus back to that tab... Very nasty behaviour indeed
Finally, after the ordeal ends, main video starts playing:
The test above was conducted on a Windows Vista SP2 32-bit Home Premium laptop, browser was latest New Moon 27 offering (v27.9.1a1, 32-bit, 2018-08-24) with lav-dll-lite-mmx dlls put correctly in place...