What happens when you enter
http://linux.server:8000 from Linux browser? Do you get Server not found error?
If that is the case then most likely your Apache service is down.
I would restart the host computer.
Start the guest computer (virtual machine).
Login into Linux panel.
Start Oracle services normally.
Now watch the status of each service when it starts. It should say 0. Note down which of the services are not starting with 0. This is where the problem is.
Then you will need to look into the log file of the services that are not starting to find out what is causing this issue.