Please can you explain the industry for me?

I have made industry zones and have next to no traffic since I put highway roads for them and one ways etc. I just got past their worker problems by building a "slum area" next to them with no school so they are uneducated to work in the industries but now they keep abandoning because:

Not enough raw materials (They suddenly started showing these messages) and not enough buyers for products. These have just shown up after a few weeks.

I cannot keep a stable industry, I have a demand for it I build industry and then I build houses like above for workers, but once I fix a problem more show up and they are constantly abounding and rebuilding all the time it is very frustrating.

What am I doing wrong?