I did a Time Machine backup without any exclusions. Later I reset my HD from the backup, and one large file did not appear. I cannot find it manually when entering Time Machine either. Any ideas on what happened to it, and how to recover it?
Where was the file located on your drive?
Root directory - Macintosh HD.
If it isn't in the Time Machine backup and you reset the disk, which I take to meet reformatted it, then no.
Okay. Any idea why this happened?
I had to reset the HD because it was a replacement due to the Apple call-back.
It is probably to late now but in the future you may want to keep an eye on the log files for Time Machine in Console for any possible warning of things failing to get backed up.
Retrieving data ...