ECU Swap? Stock file missing and scanner can’t communicate!

Hey guys, so I’ve been having this ecu problem for a while that I can’t figure out. I have a 2004 VW Jetta TDI, BEW. I purchased a custom tune from diesel dna tuning and tried to flash it to my ecu using the Powergate v3 tool. It keeps displaying an error saying “stock file not found.” I‘ve tried multiple times with the same result. The car did have a REVO Stage 1 tune installed by a shop from the previous owner, so I took it to that same shop to try to get the revo tune removed. They tried and said they weren’t able to do it. They said the ecu has probably been tampered with and that I would need to find an ecu with the same exact number and get that rekeyed. (They gave me the number on a piece of paper but I cant find it.) Apparently they hooked up a scanner and said there were no codes. I say apparently because after that I tried hooking up my OBD scanner to test for communication, and my scanner wouldn’t communicate with my ecu.

My tuner guy said it was probably a faulty k-line, so I tapped another wire on both ends of the k-line from the ecu to the OBD port. Still no communication. I’m just tired of dealing with this. Is it possible to just swap another ECU in? Does it have to be a particular code or will any 2004 BEW ecu work with an immobilizer delete? I want to get my car on it’s custom tune ASAP, otherwise that’s a chunk of wasted money. Any help is appreciated!!

Well you can get a used ECU, exact part no. then have that tuned.
I would think diesel dna would help, you might need to send them the ECU.
I doubt there was anything wrong hardware wise, but the ECU has had it's firmware wrote, maybe multiple times.

So diesel dna is going to send me an ecu and make it tuneable so I can upload their custom tune. Can’t wait to get it! Will update.