I was looking for your reply in your other thread that I just answered.
But, I just saw this new thread.
Insufficient Disc Space Available For Burning.....
That message typically points to not enough space for the burn to temporary encoding files.
When you go to Edit Menu/Preferences/Scratch Discs, what is
a. the path shown to the place where these encoding files are going to be stored
b. to the right of the path information there should be an estimate of the free hard drive space at that location - what is it?
In the burn dialog Quality area, what does it show for Space Required and Bitrate.
Do you have any other place on the computer that has more than 200 GB? We may have to change the save location
for the Encoded Files to be generated or free up more space at the location to where those encoding files are currently directed.
Let us see where the details lead us.
All of the above information should lead us to answer for the why.