VirtualBox is a free Virtual Machine software that can run a computer inside your computer. It is often used to isolate your real system from whatever you will be running inside the VM.

Terminology: your real system is called "Host" and your simulated system is called "Guest".

Reason: Your host/guest user does not have write permissions to the target/shared folder.

1. On host: check if you can create files inside the target folder.
2. On guest follow the steps below.

Find shared folder path: run command in terminal mount | grep vboxsf
If the folder was mounted, you should see highlighted lines. If not then make sure to install Guest Additions.

can-i-see-this on /media/sf_can-i-see-this type vboxsf (rw,nodev,relatime)
The path is "/media/sf_can-i-see-this" and it's read-writeable.

Change directory and try to look inside:
cd /media/; ls "sf_can-i-see-this"
The answer is no: "ls: cannot open directory 'sf_can-i-see-this': Permission denied"

Why is that? See who this folder belongs to (list all files and folders in here):
ls -l
Answer: "drwxrwx--- 1 root vboxsf 4096  24 dec 04:20 sf_can-i-see-this"
Explanation:
d = directory, we know already
rwx = root: the root user is the owner and can read/write/look inside
rwx = vboxsf: it's the group, anybody in this group can do the same
--- = anybody else is disallowed from doing anything

What's the name of my user account?
whoami
Answer: "myuser". I am definitely not root.

What groups am I in?
groups or myname=$(whoami); grep -F "$myname" /etc/group
Answer: many groups listed, including my own name (it's both a user and a group) but no "vboxsf"

Solution: Give me "vboxsf" group so I can have rwx permissions over the shared folder.

Command: sudo usermod --append --groups "vboxsf" "$(whoami)"
NOTE: You will show up in (2) group settings, but not in (1) current groups.
YOU MUST LOGOUT AND LOGIN (or reboot VM) TO APPLY NEW GROUP.

After you find yourself in the "vboxsf" group, Tixati will work with the shared folder fine.