Aruba is a provider of Internet services.
In its servers, the only folder writable, is "\ public".
I can not change the permissions of the other folders.
During installation osTicket must write to the configuration file.
I noticed that if insert the whole folder "upload" of osTicket, your installation is working properly.
I think, but I have not tried it yet, you are finished setting up, I can move osTicket where I want seamlessly, or at least I hope.
Now it remains to solve the issue of forced logins by users.