Michael,
Either your education priority for High Tech Engineers is too low. I find a priority of 20 for High Tech Engineers, with the total of all priorities adding up to 120 is usually necessary.
Alternately, your education index is too low. Personally I find an Education Index of 180 provides plenty of educated workers. However some players need an Education index of over 200.
PS. People will only be able to give specific advice relating to your country, if you include the name of your country, and the world where it is based, in your post.
Signed President of DanNation on LU