hi
im working with a .net app that crashes ildasm while decompiling, ive patched the second entry as Nikolatesla20 said in his tutorial but it stills the same!.... is there any different way to make ildasm make his job successfully?

Even if you succeed, it's just exploiting a bug in ildasm; next version will probably not be fooled by that kind of tricks.

As omega_red suggested, you can just download the beta version of the framework 2.0 and use the new ildasm to decompile your protected app. It won't crash anymore for invalid metadata.
However, have you discovered the protector used for your target?

i will try this version, the protector looks like Xencode 2005 becuase ive loaded the target in it and it shows me a message that the file is already packed with xencode.

Then, I really don't understand. Are you talking about the tutorial from Nikolatesla20 about Salamnder Obfuscator? If yes, why you tried to apply it to a XenoCode protection?
Try to find something about your target protector instead, like this for example:

hxxp://www.exetools.com/forum/showthread.php?t=7188

i found that later after posting the thread, thank u very much for replying fast