Slideshow creates 70 GByte in Velo folder and Lightroom crashes

Sahil,
I probably post this answer again as a hint:
The problem with generating slideshows in LR is, that LR creates enormous amount of cache data - in my case LR created close to a 100 Gbyte for a 10 Gbyte video, made from 600 slides and 100 clips. I freed 70 Gbyte on my small SSD, but that was not enough to let LR create that slideshow.
LR seems to have a dedicated cache for slideshows: (this all relates to Win10)
C:\Users\XXX\AppData\Local\Adobe\Lightroom\Caches\velo
There are also the video cache in Cache.

LR does not have a setting to re-locate that “velo” cache. So, if the C drive is too small, then there is no slideshow. So I thought.
But then I discovered the mklink command. It has to be executed as admin within the win command line editor. Then it will allow the velo cache to be redirected to any other disk with enough space (this works for all caches). This is of course not good for daily work, where one wants the cache to sit on the SSD for speed, but for special cases it might be useful.

It goes like that:
First rename or delete the old “velo” folder (=velo1)
Then create a new “velo” folder on another drive (W in my example)
Then run
mklink /j C:\Users\XXX\AppData\Local\Adobe\Lightroom\Caches\velo W:\velo
from a command terminal. XXX stand for the actual user.
Done. From now on all files that are send to “velo” end up in the new “velo” destination.
Windows may have created a new user name for you with you knowing, so you might not be aware under which username you should look. Try the free software TreeSize to check folder sizes and you will find the Adobe caches for sure and probably be surprised and ask yourself if Adobe want to sell hard-disks too…