I did following
and they were successful but the apps page still will not come up. It use to come up after I install the product but now it what come up.

First ping linux.server from your host (client) computer and see if it is translating to the IP address of your server.
Then see if Oracle services are up and running on the server. Stop (adstpall.sh) them and restart (adstrtal.sh) them if need be

I was able to bring up the login page to the apps before and now I keep getting this message when I type http://linux.server:8000/

linux.server is not setup to establish a connect on a port 8000 with this computer.

Do you know what is causing this now.
I did the following below:
ping linux.server from my host (client) computer and it worked.
I Stopped (adstpall.sh) then restart (adstrtal.sh) the apps. Everthing same to work. What could be stopping the page from coming up?

Find out the ip address of your linux server.

/sbin/ifconfig

Then see if you can see Oracle login page using the ip address instead:

http://192.168.2.3:8000

If not then most likely your apache server is down.
Otherwise verify the settings in your host file.

When you started the services, did everything start successfully (without errors)? Verify exit status codes for services. Are they 0?

I have the same problem. Can you help please?

Two questions:
1) Do you see the login page using the IP address? For example:
http://192.168.2.3:8000
2) When you started the services, did everything start successfully (without errors)? Verify exit status codes for services. Are they 0?