Cities Skylines tells me on top of building icon: "not enough buyers for products", how to fix?
Industrial buildings reports "not enough buyers for products", this usually means that you have either too many industrial buildings or too few commercial buildings. It can also mean your import / export, outside connections (road, train, ship, airport), is not working or even present.
Traffic routes can also cause this issue, if you have huge traffic jams between industrial zone, commercial zone and/or outside connections, well you got a problem.
Traffic is the key, trust me on this one. Create six lane straight roads with few intersections to move your semi-trucks, vans, box trucks etc fast from A to B across the city.
See also:
Highway
Roads
Roundabout
Traffic Jam