Not a lot to go on. My best guess is that the backup is from a different SQL instance. And SQL can't find the restore path locally that matches the one that's coming from the back up.
Just a guess, as the restore process is running for a while and then getting the error.
Can you try enabling Instant File Initialization and run the restore again.
what version is the sql server from which the bak file is taken from?
what version is the target sql server you are trying to restore to?
does the db already exist in the target sql server you are restoring to?