The requested URL /oa_servlets/Appslogin was not found on this server.

While browsing through open TARs, I found one raised by the DBAs for an issue after upgrading an 11.5.8 instance to 11.5.10.2 and then implementing shared application file system. Here's the issue:

Go to: http://clone1.justanexample.com:8000
Click on the link: E-Business Home Page.
You get this error:

Not Found

The requested URL /oa_servlets/Appslogin was not found on this server.

HTTP-404 or not found error.

I had solved a similar problem which I have described in a previous post. So I worked on the same lines and found that OAM worked fine without issues. I then checked the value of s_login_page by giving the command:

grep s_login_page $CONTEXT_FILE

It was correctly set to
http://clone1.justanexample.com:8000/oa_servlets/Appslogin

I was wondering what else could be wrong, when I looked again. Appslogin was spelled with a small l. Appslogin should be spelt AppsLogin with capital L. I immediately tested for the URL by replacing small l with capital L:

http://clone1.justanexample.com:8000/oa_servlets/AppsLogin

It worked fine. So solving the problem would require changing the value of s_login_page so that it contains AppsLogin instead of Appslogin and then running autoconfig. A very simple problem, but difficult to trace, unless you train your mind to observe.