Do I need to (and how) re-generate wsdl after I modify it?

Hi, I have to edit a vendor's wsdl on our server to change a variable to allow for null.  However, after I save the wsdl, the change is saved no problem however, when I type in url to open the wsdl it doesn't show the changes.  Is it because I have to regenerate or do something else to it?  The vendor's program is written in Java.  I'm using C# and I need to set a datetime variable to null hence the modificaiton.

I did search the only server drive, C, and there is only this copy of wsdl.  The changes is saved when I open it using Notes++.

thank you.