Glad you worked around it.
I suppose you got Mulva's
x264 encodes here on TPB.
HEVC/x265 (encoding/decoding) is much more *****U-intensive than x264. That is probably the reason why you are experiencing difficulties. In case you have some background jobs running, try stopping them.
Reg., Planet Earth II, MVGroup has also uploaded the series in two other versions.
1) HDTV : 1280x720; x264
2) PDTV : 832 x 468; x264
I couldn't find any x264 1080p versions.
It is possible to convert from x265 to x264 format. However it is a time consuming process, unless you have a 'powerful' *****U.
A Intel dual-core takes about a minute to convert a 15 second clip.
But you should be able to play Dr.XJ's HEVC encodes with ease.
Anyway, just wanted to say, don't give up on HEVC/x.265.