I have my Ubuntu installed on an SSD, and a secondary HDD called Earth that I've set to automatically mount at startup. The thing is, when it mounts, the folder is labelled "Earth1" instead of "Earth". There is still a folder in /media/username called "Earth" but when I attempt to open it, it gives the error:

This location could not be displayed. You do not have the permissions necessary to view the contents of 'Earth'.

So right now a whole bunch of programs are trying to access files in /media/username/Earth but returning errors.

This has been happening since I had a problem with Unity and had to reset some of my user settings. I'm currently logged in as admin, and I've checked the startup command and everything's fine there.

Update 2017-10-31 (for future reference)

I was using Startup Applications to mount Earth (BTW, Startup Applications runs at login, not at boot). Based on subin's answer, I switched to using the Disks utility, which saves its config to the /etc/fstab file (which tells the system to mount partitions at boot), and that worked fine. The fstab entry specified the mount point.