cities-skylines
Specialized industries (forestry, mining, etc) require relatively uneducated workers. Unfortunately, I placed a strong emphasis on education in my city, and over half the population (including children) have university degrees. Not really suitable for doing grunt work.
So if my education system is so top notch, how do I attract the uneducated folk to my fine city so that they can work the mines?
After some testing myself, I discovered this message means your industries are lacking one or more of your basic services such as fire protection, police, mass transit, etc. Placing offices near polluting industries can cause the "Too few services" message because of low land value. What the message actually is saying is: there is something undesirable about coverage or the location. In my case it was fire:
This was my fire coverage before I added a fire station.
And this is after. The messages all disappeared within a few seconds. If you are getting this message, be sure to check all your overlays to see what they are lacking!
Along with the "big" city services like education and fire, there are a few other things to check and to provide if you want your buildings to upgrade.
The first that I would suggest you look at is public transit. Any kind will do, buses, subways, trains, whatever.
The next thing to look at is your data overlays. What's the pollution like in the area? Noise? Upgrading the nearby streets to be tree-lined improves noise pollution and can make people happy.
As a general principle, anything that makes those little smiley faces pop up over the buildings is increasing their happiness and moving them towards upgrading.
Note that these work for any kind of building that can upgrade, including industry. Non-office industry once upgraded produces less pollution and employs higher educated citizens. Just noting this because its something that I see a lot of people neglect (Parks? In my industrial area?!).
Best Answer
I think you are under the assumption that Highly Educated Workers cannot work the Uneducated jobs.
They indeed will eventually fill whatever jobs are available. At first they may not want to go work there, and the dirty industries may complain when they first go into business that there are no workers, but the Highly Educated will eventually go work there. The industry itself will display that they are "overeducated" — which doesn't appear to impact its performance any. So feel free to send those university degree children to the mines :D
Of course, theoretically if they went to work these lower jobs and you had some Highly Educated positions somewhere else, they wouldn't be available for those jobs. But then again you have no real way to control of who-works-where anyway.