Salem

I found myself a metal node, so I tried to build a mine entrance on it. Too bad that it says that I can't build it there, the ground is flat too... So the only thing I could think of, do I need more black bile? My BB is 10

Did you equip the rod and prospect while placing the mine? You need to see it while placing the structure for it to work.

I did that, still the same problem.

Could be:

Wrong terrain type to build on (can't build on some terrain types like clay or sand) or the terrain type has to be "prepared" so you can build on it--make sure the ground is completely dug up (don't think you need to go so far as to pave the land right now)

Too close to a terrain feature (such as water)--might try moving the mine off grid some. No idea if this will actually work or not, but someone else reported that it does.

There is no water, sand or clay anywhere near this node.. I even tried paving the area where the node was.. But what do you mean with ''dug up''?

EDIT: Nvm I solved it, just had to dig and refill the ground around the node again.

That. Certain types of terrain, such as forests, don't let you build directly on them. Instead, the ground has to be dirt or paved. For now, I'm not aware that any buildings require pavement. Early on this was questioned if this was working right (as Haven required nearly everything to be on pavement or decay whether or not it was on an active claim), but at this point, it could just be considered a feature. Still a chance it could be changed in the future.