I had the LE code and found one broken red wire in the tar-like stuff. The cut was also pretty clean, as if it had been cut by a knife. Another wire had a cut, but only in the insulation. Repaired both and separated all the wires from the tar substance. It did the trick.
I like the idea of applying some material on the tar to let the wires slide freely. I think I'll reopen and do just that.
Many thanks to those who posted their solution!