So, I encountered the several times cited here fault 61 on NDX-537E (Fault 61 - BridgeCo init fail). Fixed it just like DR3 said ( PSA: NDX BridgeCo fault codes 59 & 61 FIXED ) only expanding a bit the treatment. I have unplugged all the the white ribbon cables and other connectors to unscrew and remove the streaming module plate. It appeared that the loosest connection was the one on the main board end. Reconnecting all the wires was all I needed to make the NDX work again. Simple and free of charge. No re-upgrades needed.
Thank you DR3 