Thanks for the updates, yes I am on windows and I assumed windows was having a rough time reading the file.  I thought it was somehow just a segment of blocks  at first so I would do 10 to 100k blocks and retry but the full bootstrap never worked again, so I moved to appending 100k files at a time and determined it's a windows thing. (Windows 10)  The last 2 days I had work, so I've moved up to 200k blocks at a time and am currently 35 weeks behind.

The 10k block files were definitely useful and I would not have known to append them had you not mentioned it in your post, although 100k files may be more than enough if you're finding doing 10k at a time is tedious. (It seems tedious). 

Since I had problems around 1.9 million blocks, windows users may need that bootstrap file broken into 2 or 3 parts to avoid this happening to them.