ADF Model: java.lang.NullPointerException at oracle.adf.model.binding.DCIteratorBinding.getSortCriteria

If you encountered this error though your code was running good before, then welcome to the club! :D
Here are some of our colleagues:
ADF webapp deployment problem...
JDBC connection for ADF
Both of them have resolve their case by recreating their application and build it from scratch. Yaiks! We sure cannot afford that on an app that we build for months.

Luckily, I was able to resolve my case by doing the steps below, but in your case, I don't know, so good luck!

It could be resolved by doing the following:

1. Open the page definition of the target page that cause this error
   
2. Find the method action that supports the page like ("findEmployeeById")
   
3. Copy it to notepad for later reference
   
4. Delete it. delete it even though that it is properly defined
   
5. Recreate the method action above (i did it thru the overview tab)
   
6. Run
   

Did it work?
Can somebody explain this for me?!!

Cheers!