I agree. Its one thing to have cross-posted articles, but with questions like this, the OP is never going to see it so it feels like a complete waste of time.
I've heard diagonal cracks like this are bad news, I wonder if that plate of steel was put there by the previous owner to hold it together, I'd measure and record how big they are and keep checking if they are getting bigger.
Find a civil engineer or a structures engineer and ask them.
That crack does not look good. If I remember correctly cracks with more than 1mm gap should not be ignored.
If you don't want to follow any of the previous advise, carefully monitoring for movement on the crack on a medium to long timeframe is, IMHO, the most irresponsible you can be.