I was playing the 32 bits version and... for me, everything was going well until the end of the first major sex scene of the last chapter, then I had a lot of issues/crashes, not always the same (Exceptions: error(u'Failed to decode WEBP',) & error(u'Failed to allocate SDL_Surface',), Out of memory,...) or in the same point, but in the same "area" and I can’t go much further.
Since Windows 10 should be able to decode webp (you did mention having Windows 10 32-bit?), I'd say this is a general running out of memory problem. Have you closed all other apps running in the background, especially any browsers?
In case you have, then the 4GB address space of the 32-bit Windows is probably just not enough to run both, Windows 10 and a modern Ren'Py game with FullHD webp videos simultaneously.
I mean, I have been running Ren'Py games on a 15 year old PC with 8GB of RAM and a 10 year old graphics card and I still have to shut down other programs quite often to be able to run them. Although 32-bit software uses less RAM, I can't really imagine running Windows 10 and anything useful on it, having just 4GB of RAM + VRAM combined (mostly because I've been too lazy to build a new PC)
You know, you could just install Windows 10 64-bit using exactly the same licence key? The only thing you need is more RAM.
You could even get 4GB DDR2 or DDR3 RAM modules for free these days, if you know someone who has some old hardware lying around.
It seems that even brand new (or rather, unused) 4GB DDR2 costs around 30€ in the store, 4GB DDR3 less than 15€ and 8GB around 20€ (assuming you agree to wait a couple of weeks for the delivery).
I guess the prices of old types of RAM have finally dropped lower than I expected.