There is another problem I found:

You did not save the xml file at the standard place.

Normally, you will select a workspace
For example: d:\EJS_4.2.7\workspace or any place like d:\ejsworkspace
There are four subdirectory under the above workspace

We should put our xml source under source.

There is a sub-directory under source called users. That is the place for users to save his/her own xml files.
To avoid conflict between users (e.g. two users both create pendulum.xml ), so sub-directory are suggested.

For example: I save all my xml files under
where ntnu is the university where I did my work. fkh is for myself.
If there is other user at my university, then he/she is suggested to put file under workspace\users\ntnu\xxx where xxx is his/her own identity.

I would suggest you save your xml file under workspace\users\br\ahmed or something else
However, it has to be at least under workspace\users to work.
I believe you save your files at workspace\ahmed , that is the reason why the uploaded jar file did not work. Because it might conflict with others.
Please move you directory ahmed under users (becomes users/ahmed or users/br/ahmed or ...)
and it should work.