Can't create Data Objects!

Installed on AWS from the PIMCore AMI, when I go to create a Blog article of anything else I get the message…

“Failed to create new item, please try again.”
“Cannot save version for element 155 with type object because the file /opt/bitnami/apps/pimcore/htdocs/var/versions/object/g0/155/202 is not writeable.”

Infact, in the g0 folder there is no folder called 155. It’s like the system has lost rights to create new files and folders.

Anyone come across this before?