You must make sure your flash drive is formated with an exfat filesystem before you can mount it as an exfat file system. Also check the integrity of the format before using the device by using a standard partitioning program that has the capability to check for exFat format integrity. You'll have to search for such a program.
Also note that NTFS is reported to shorten the lifespan of flash drives due to using more read write operations on the device then Fat, Fat32, or exFat file systems do.
If you are moving files larger then 4GB to the device then exFat is a better choice noting that exFat has been reported to not be as well supported by Mac or Linux systems yet. Where "well supported" means the functionality is present and functioning without having to install extra tools or make extra configurations after a first install of the Operating System.
In the error you have shown, pagefile.sys is reporting a size of 0, when the mount program was expecting a size of 8565587968. This could mean a number of different things but in general this is due to the file system not being recognized correctly. For example this could mean that exFat isn't implemented correctly in Linux yet, or that the drive wasn't formated correctly to an exFat filesystem, or that something else went wrong.