Possible fixes: 1) increase you high schools so they generate more LLWs....which eventually will work their way up to HLWs. 2) You can change the professions of some of your other worker classes and move workers back to HLWs
If you have a lot of corps that hire high techs or executives, your universities might be retraining those workers using the HLWs when the high techs or executives retire. I've noticed this in my countries as well. If you have enough of these, you could even reduce the education priorities for a while in those worker classes to help balance out your workforce.
But we do have a shortage of HLWs in many countries. we are making small changes that will reduce the number of HLWs needed. This was done twice already and more is underway.
the Medium Level Workers is also shortage on supplies that needed for the corporations, could you please fix this problem again and have another look over in my Country please, it is on Little upsilon, called the Lions Cub Region with the Country name called The Little Upsilon Town. Thank you for you're patience.