Hey, @Kyoketsu9513! Check out this thread: "file.so" preventing drive from unmounting - #12 by winnie
Does it sound like your issue? Just letting you know not to give up or worry, as your problem might be resolved with the next updates of KDE Framework.
Here is the main bug report (with duplicate reports in the comments): 434455 – kinit doesn't terminate "file.so" and the partition cannot be unmounted.
You can get around this in the meantime by ending the processes named “file.so” before attempting to eject/unmount the external drive or network share.