VHS tape has one "cog" blocked off - can't play it I'm converting some old VHS tapes to DVD, and all is going well.

The last VHS tape, however, is different than the others. Where you would normally have 2 "cogs" for the two reels, this tape only has one, while the takeup wheel "cog" is more or less blocked off:





When I insert the tape, it doesn't go down all the way into the player (I'm assuming because the plastic piece above is blocking where the gear would normally go). The VHS player panics, and spits the tape out.

How can I resolve this? And to satisfy my curiosity, what is this piece and why is it there?
So, I posted these images to Reddit under /r/whatisthisthing, and the answer that came back was obvious once it was offered:

Someone has taken a normal tape apart and re-assembled it with the take up spool upside-down.
It can't be a cleaning tape because it will not engage with the take up spool drive. A machine might just spit it back out but it could slam into the drive mechanism and cause some damage.

You will have to take the cartridge apart and carefully flip the spool over. No telling what other nonsense might be going on inside that cassette, however. So standard YMMV disclaimer applies.