How to get the source of a hacked client / editing with FFDec without errors?

[DavisXola]

I want to edit a client. In the past I used to use CC's source back when it was up to date by CrazyJani. If I try to edit an existing hacked client with FFDec, even without touching anything, once I press "edit ActionScript", most of the times I try to edit I get errors that aren't even related to what I did and and were there before I edited it.
Is there any way of either editing through FFDec or get a source of the client?

[Gravitir3.14]

Look this thread.
Now it's easy to update source to current version, ~120 files changed and some assets/dat changed.
I have the source code of a prod client and of course CC, but it would be better if you learned to update it for yourself.
If need help - pm me.

[DavisXola]

Look this thread.
Now it's easy to update source to current version, ~120 files changed and some assets/dat changed.
I have the source code of a prod client and of course CC, but it would be better if you learned to update it for yourself.
If need help - pm me.

I'll check it out, thanks!