If you are receiving a 500 / Internal Server error after each attempt to save an edited page, check to see if the script is redirecting you to the wrong page. You can generally see where it is directing you by looking up in the URL bar of your browser. If it's redirecting you improperly, then $FullUrl may fix the problem.
For example, it may be directing you to the following address:
In this case, the proper redirect address is as follows:
Setting your $RedirType to 3 may prevent the internal error, but does not solve the problem, as even the links on the non-redirect page are incorrect.