Is the drive partioned and one partition is full or nearly so?
Thank you for your post.
Even though you have a FileMaker Pro database file on a jump drive, FileMaker Pro will write a Temp folder to the System drive with enough information to load the database file. If there is not enough room on the System drive, you will then receive the error message. You will also receive the error message if the System drive does not have read/write privileges for that user account.