Robocode Editor/Compiler troubles?

I tried your suggestion. Robocode still gets the errors, but now it goes through them in a matter of seconds, which I can accept.

Whenever I tried the Robot Editor, I got this message:

Please wait while Robocode sets up a compiler for you...

Setting up compiler
Java home is <CENSORED>\jre6

Testing compile with Java Compiler (javac)
Java Compiler (javac) does not exists or cannot compile.
Testing compile with Eclipse Compiler for Java (ECJ)
Eclipse Compiler for Java (ECJ) was found and is working.

Compiler has been set up successfully.
Click OK to continue.

I assume I deleted something important when I was deleting robots, that Robocode had to rebuild, or search for and update references, or something else like that.

Anyway, Robocode works for me now (though testing will be a bit harder), so I thank you all for your help.